diff --git a/AirplaneWithRadar/AirplaneWithRadar/AirplanesGenericCollection.cs b/AirplaneWithRadar/AirplaneWithRadar/AirplanesGenericCollection.cs
index da11b7b..a65fb60 100644
--- a/AirplaneWithRadar/AirplaneWithRadar/AirplanesGenericCollection.cs
+++ b/AirplaneWithRadar/AirplaneWithRadar/AirplanesGenericCollection.cs
@@ -56,13 +56,13 @@ namespace AirplaneWithRadar.Generics
         /// <param name="collect"></param>
         /// <param name="obj"></param>
         /// <returns></returns>
-        public static int operator +(AirplanesGenericCollection<T, U> collect, T? obj)
+        public static bool operator +(AirplanesGenericCollection<T, U> collect, T? obj)
         {
             if (obj == null)
             {
-                return -1;
+                return false;
             }
-            return collect?._collection.Insert(obj) ?? -1;
+            return (bool)collect?._collection.Insert(obj);
         }
         /// <summary>
         /// Перегрузка оператора вычитания
@@ -73,7 +73,7 @@ namespace AirplaneWithRadar.Generics
         public static bool operator -(AirplanesGenericCollection<T, U> collect, int
         pos)
         {
-            T? obj = collect._collection.Get(pos);
+            T? obj = collect._collection[pos];
             if (obj != null)
             {
                 collect._collection.Remove(pos);
@@ -87,7 +87,7 @@ namespace AirplaneWithRadar.Generics
         /// <returns></returns>
         public U? GetU(int pos)
         {
-            return (U?)_collection.Get(pos)?.GetMoveableObject;
+            return (U?)_collection[pos]?.GetMoveableObject;
         }
         /// <summary>
         /// Вывод всего набора объектов
@@ -126,25 +126,18 @@ namespace AirplaneWithRadar.Generics
         /// <param name="g"></param>
         private void DrawObjects(Graphics g)
         {
-            T? t;
-            int Rows = _pictureWidth / _placeSizeWidth;
-            int diff = 1;
-            int currWidth = 0;
-            for (int i = 0; i < _collection.Count; i++)
+            int i = 0;
+            foreach (var airplane in _collection.GetAirplanes())
             {
-                currWidth++;
-                if (currWidth > Rows)
+                if (airplane!= null)
                 {
-                    diff++;
-                    currWidth = 1;
-                }
-                t = _collection.Get(i);
-                if (t != null)
-                {
-                    
-                    t.SetPosition((Rows - 1 - (i % Rows)) * _placeSizeWidth, i / Rows * _placeSizeHeight);
-                    t.DrawTransport(g);
+                    airplane.SetPosition((i % (_pictureWidth / _placeSizeWidth)) * _placeSizeWidth, (i / (_pictureWidth / _placeSizeWidth)) * _placeSizeHeight);
+                    if (airplane is DrawningAirplaneWithRadar)
+                        (airplane as DrawningAirplaneWithRadar).DrawTransport(g);
+                    else airplane.DrawTransport(g);
+                    airplane.DrawTransport(g);
                 }
+                i++;
             }
         }
     }
diff --git a/AirplaneWithRadar/AirplaneWithRadar/AirplanesGenericStorage.cs b/AirplaneWithRadar/AirplaneWithRadar/AirplanesGenericStorage.cs
new file mode 100644
index 0000000..c15272c
--- /dev/null
+++ b/AirplaneWithRadar/AirplaneWithRadar/AirplanesGenericStorage.cs
@@ -0,0 +1,82 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using AirplaneWithRadar.DrawningObjects;
+using AirplaneWithRadar.MovementStrategy;
+
+namespace AirplaneWithRadar.Generics
+{
+    /// <summary>
+    /// Класс для хранения коллекции
+    /// </summary>
+    internal class AirplanesGenericStorage
+    {
+        /// <summary>
+        /// Словарь (хранилище)
+        /// </summary>
+        readonly Dictionary<string, AirplanesGenericCollection<DrawningAirplane,
+        DrawningObjectAirplane>> _airplaneStorages;
+        /// <summary>
+        /// Возвращение списка названий наборов
+        /// </summary>
+        public List<string> Keys => _airplaneStorages.Keys.ToList();
+        /// <summary>
+        /// Ширина окна отрисовки
+        /// </summary>
+        private readonly int _pictureWidth;
+        /// <summary>
+        /// Высота окна отрисовки
+        /// </summary>
+        private readonly int _pictureHeight;
+        /// <summary>
+        /// Конструктор
+        /// </summary>
+        /// <param name="pictureWidth"></param>
+        /// <param name="pictureHeight"></param>
+        public AirplanesGenericStorage(int pictureWidth, int pictureHeight)
+        {
+            _airplaneStorages = new Dictionary<string,
+            AirplanesGenericCollection<DrawningAirplane, DrawningObjectAirplane>>();
+            _pictureWidth = pictureWidth;
+            _pictureHeight = pictureHeight;
+        }
+        /// <summary>
+        /// Добавление набора
+        /// </summary>
+        /// <param name="name">Название набора</param>
+        public void AddSet(string name)
+        {
+            if (_airplaneStorages.ContainsKey(name))
+                return;
+            _airplaneStorages[name] = new AirplanesGenericCollection<DrawningAirplane,
+                DrawningObjectAirplane>(_pictureWidth, _pictureHeight);
+        }
+        /// <summary>
+        /// Удаление набора
+        /// </summary>
+        /// <param name="name">Название набора</param>
+        public void DelSet(string name)
+        {
+            if (!_airplaneStorages.ContainsKey(name))
+                return;
+            _airplaneStorages.Remove(name);
+        }
+        /// <summary>
+        /// Доступ к набору
+        /// </summary>
+        /// <param name="ind"></param>
+        /// <returns></returns>
+        public AirplanesGenericCollection<DrawningAirplane, DrawningObjectAirplane>?
+        this[string ind]
+        {
+            get
+            {
+                if (_airplaneStorages.ContainsKey(ind))
+                    return _airplaneStorages[ind];
+                return null;
+            }
+        }
+    }
+}
diff --git a/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.Designer.cs b/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.Designer.cs
index 6d380a3..48be20a 100644
--- a/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.Designer.cs
+++ b/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.Designer.cs
@@ -29,43 +29,102 @@
         private void InitializeComponent()
         {
             groupBoxInstruments = new GroupBox();
+            groupBoxSets = new GroupBox();
+            buttonDeleteSet = new Button();
+            listBoxStorages = new ListBox();
+            buttonAddInSet = new Button();
+            textBoxStorageName = new TextBox();
             maskedTextBoxNumber = new MaskedTextBox();
             buttonUpdate = new Button();
             buttonAdd = new Button();
             buttonDelete = new Button();
             pictureBoxCollection = new PictureBox();
             groupBoxInstruments.SuspendLayout();
+            groupBoxSets.SuspendLayout();
             ((System.ComponentModel.ISupportInitialize)pictureBoxCollection).BeginInit();
             SuspendLayout();
             // 
             // groupBoxInstruments
             // 
+            groupBoxInstruments.Controls.Add(groupBoxSets);
             groupBoxInstruments.Controls.Add(maskedTextBoxNumber);
             groupBoxInstruments.Controls.Add(buttonUpdate);
             groupBoxInstruments.Controls.Add(buttonAdd);
             groupBoxInstruments.Controls.Add(buttonDelete);
             groupBoxInstruments.Dock = DockStyle.Right;
-            groupBoxInstruments.Location = new Point(699, 0);
-            groupBoxInstruments.Margin = new Padding(2, 2, 2, 2);
+            groupBoxInstruments.Location = new Point(707, 0);
+            groupBoxInstruments.Margin = new Padding(2);
             groupBoxInstruments.Name = "groupBoxInstruments";
-            groupBoxInstruments.Padding = new Padding(2, 2, 2, 2);
-            groupBoxInstruments.Size = new Size(170, 497);
+            groupBoxInstruments.Padding = new Padding(2);
+            groupBoxInstruments.Size = new Size(214, 570);
             groupBoxInstruments.TabIndex = 5;
             groupBoxInstruments.TabStop = false;
             groupBoxInstruments.Text = "Инструменты";
             // 
+            // groupBoxSets
+            // 
+            groupBoxSets.Controls.Add(buttonDeleteSet);
+            groupBoxSets.Controls.Add(listBoxStorages);
+            groupBoxSets.Controls.Add(buttonAddInSet);
+            groupBoxSets.Controls.Add(textBoxStorageName);
+            groupBoxSets.Location = new Point(14, 33);
+            groupBoxSets.Name = "groupBoxSets";
+            groupBoxSets.Size = new Size(182, 313);
+            groupBoxSets.TabIndex = 6;
+            groupBoxSets.TabStop = false;
+            groupBoxSets.Text = "Наборы";
+            // 
+            // buttonDeleteSet
+            // 
+            buttonDeleteSet.Location = new Point(9, 223);
+            buttonDeleteSet.Margin = new Padding(2);
+            buttonDeleteSet.Name = "buttonDeleteSet";
+            buttonDeleteSet.Size = new Size(166, 30);
+            buttonDeleteSet.TabIndex = 9;
+            buttonDeleteSet.Text = "Удалить набор";
+            buttonDeleteSet.UseVisualStyleBackColor = true;
+            buttonDeleteSet.Click += buttonDeleteSet_Click;
+            // 
+            // listBoxStorages
+            // 
+            listBoxStorages.FormattingEnabled = true;
+            listBoxStorages.ItemHeight = 20;
+            listBoxStorages.Location = new Point(14, 111);
+            listBoxStorages.Name = "listBoxStorages";
+            listBoxStorages.Size = new Size(152, 84);
+            listBoxStorages.TabIndex = 8;
+            listBoxStorages.SelectedIndexChanged += listBoxStorages_SelectedIndexChanged;
+            // 
+            // buttonAddInSet
+            // 
+            buttonAddInSet.Location = new Point(9, 65);
+            buttonAddInSet.Margin = new Padding(2);
+            buttonAddInSet.Name = "buttonAddInSet";
+            buttonAddInSet.Size = new Size(166, 30);
+            buttonAddInSet.TabIndex = 7;
+            buttonAddInSet.Text = "Добавить в набор";
+            buttonAddInSet.UseVisualStyleBackColor = true;
+            buttonAddInSet.Click += buttonAddInSet_Click;
+            // 
+            // textBoxStorageName
+            // 
+            textBoxStorageName.Location = new Point(9, 33);
+            textBoxStorageName.Name = "textBoxStorageName";
+            textBoxStorageName.Size = new Size(162, 27);
+            textBoxStorageName.TabIndex = 0;
+            // 
             // maskedTextBoxNumber
             // 
-            maskedTextBoxNumber.Location = new Point(31, 142);
-            maskedTextBoxNumber.Margin = new Padding(2, 2, 2, 2);
+            maskedTextBoxNumber.Location = new Point(51, 425);
+            maskedTextBoxNumber.Margin = new Padding(2);
             maskedTextBoxNumber.Name = "maskedTextBoxNumber";
             maskedTextBoxNumber.Size = new Size(119, 27);
             maskedTextBoxNumber.TabIndex = 5;
             // 
             // buttonUpdate
             // 
-            buttonUpdate.Location = new Point(18, 247);
-            buttonUpdate.Margin = new Padding(2, 2, 2, 2);
+            buttonUpdate.Location = new Point(38, 509);
+            buttonUpdate.Margin = new Padding(2);
             buttonUpdate.Name = "buttonUpdate";
             buttonUpdate.Size = new Size(142, 50);
             buttonUpdate.TabIndex = 4;
@@ -75,10 +134,10 @@
             // 
             // buttonAdd
             // 
-            buttonAdd.Location = new Point(18, 53);
-            buttonAdd.Margin = new Padding(2, 2, 2, 2);
+            buttonAdd.Location = new Point(30, 369);
+            buttonAdd.Margin = new Padding(2);
             buttonAdd.Name = "buttonAdd";
-            buttonAdd.Size = new Size(142, 30);
+            buttonAdd.Size = new Size(166, 30);
             buttonAdd.TabIndex = 1;
             buttonAdd.Text = "Добавить самолет";
             buttonAdd.UseVisualStyleBackColor = true;
@@ -86,8 +145,8 @@
             // 
             // buttonDelete
             // 
-            buttonDelete.Location = new Point(18, 171);
-            buttonDelete.Margin = new Padding(2, 2, 2, 2);
+            buttonDelete.Location = new Point(38, 456);
+            buttonDelete.Margin = new Padding(2);
             buttonDelete.Name = "buttonDelete";
             buttonDelete.Size = new Size(142, 30);
             buttonDelete.TabIndex = 3;
@@ -99,9 +158,9 @@
             // 
             pictureBoxCollection.Dock = DockStyle.Fill;
             pictureBoxCollection.Location = new Point(0, 0);
-            pictureBoxCollection.Margin = new Padding(2, 2, 2, 2);
+            pictureBoxCollection.Margin = new Padding(2);
             pictureBoxCollection.Name = "pictureBoxCollection";
-            pictureBoxCollection.Size = new Size(699, 497);
+            pictureBoxCollection.Size = new Size(707, 570);
             pictureBoxCollection.SizeMode = PictureBoxSizeMode.AutoSize;
             pictureBoxCollection.TabIndex = 6;
             pictureBoxCollection.TabStop = false;
@@ -110,14 +169,16 @@
             // 
             AutoScaleDimensions = new SizeF(8F, 20F);
             AutoScaleMode = AutoScaleMode.Font;
-            ClientSize = new Size(869, 497);
+            ClientSize = new Size(921, 570);
             Controls.Add(pictureBoxCollection);
             Controls.Add(groupBoxInstruments);
-            Margin = new Padding(2, 2, 2, 2);
+            Margin = new Padding(2);
             Name = "FormAirplaneCollection";
             Text = "FormAirplaneCollection";
             groupBoxInstruments.ResumeLayout(false);
             groupBoxInstruments.PerformLayout();
+            groupBoxSets.ResumeLayout(false);
+            groupBoxSets.PerformLayout();
             ((System.ComponentModel.ISupportInitialize)pictureBoxCollection).EndInit();
             ResumeLayout(false);
             PerformLayout();
@@ -130,5 +191,10 @@
         private GroupBox groupBoxInstruments;
         private PictureBox pictureBoxCollection;
         private MaskedTextBox maskedTextBoxNumber;
+        private GroupBox groupBoxSets;
+        private Button buttonDeleteSet;
+        private ListBox listBoxStorages;
+        private Button buttonAddInSet;
+        private TextBox textBoxStorageName;
     }
 }
\ No newline at end of file
diff --git a/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.cs b/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.cs
index 1fae88c..393d53b 100644
--- a/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.cs
+++ b/AirplaneWithRadar/AirplaneWithRadar/FormAirplaneCollection.cs
@@ -21,16 +21,82 @@ namespace AirplaneWithRadar
         /// <summary>
         /// Набор объектов
         /// </summary>
-        private readonly AirplanesGenericCollection<DrawningAirplane,
-        DrawningObjectAirplane> _airplanes;
+        private readonly AirplanesGenericStorage _storage;
         /// <summary>
         /// Конструктор
         /// </summary>
         public FormAirplaneCollection()
         {
             InitializeComponent();
-            _airplanes = new AirplanesGenericCollection<DrawningAirplane,
-                DrawningObjectAirplane>(pictureBoxCollection.Width, pictureBoxCollection.Height);
+            _storage = new AirplanesGenericStorage(pictureBoxCollection.Width, pictureBoxCollection.Height);
+        }
+        /// <summary>
+        /// Заполнение listBoxObjects
+        /// </summary>
+        private void ReloadObjects()
+        {
+            int index = listBoxStorages.SelectedIndex;
+            listBoxStorages.Items.Clear();
+            for (int i = 0; i < _storage.Keys.Count; i++)
+            {
+                listBoxStorages.Items.Add(_storage.Keys[i]);
+            }
+            if (listBoxStorages.Items.Count > 0 && (index == -1 || index
+            >= listBoxStorages.Items.Count))
+            {
+                listBoxStorages.SelectedIndex = 0;
+            }
+            else if (listBoxStorages.Items.Count > 0 && index > -1 &&
+            index < listBoxStorages.Items.Count)
+            {
+                listBoxStorages.SelectedIndex = index;
+            }
+        }
+        /// <summary>
+        /// Добавление набора в коллекцию
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void buttonAddInSet_Click(object sender, EventArgs e)
+        {
+            if (string.IsNullOrEmpty(textBoxStorageName.Text))
+            {
+                MessageBox.Show("Не все данные заполнены", "Ошибка",
+                MessageBoxButtons.OK, MessageBoxIcon.Error);
+                return;
+            }
+            _storage.AddSet(textBoxStorageName.Text);
+            ReloadObjects();
+        }
+        /// <summary>
+        /// Выбор набора
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void listBoxStorages_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            pictureBoxCollection.Image =
+            _storage[listBoxStorages.SelectedItem?.ToString() ?? string.Empty]?.ShowAirplanes();
+
+        }
+        /// <summary>
+        /// Удаление набора
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void buttonDeleteSet_Click(object sender, EventArgs e)
+        {
+            if (listBoxStorages.SelectedIndex == -1)
+            {
+                return;
+            }
+            if (MessageBox.Show($"Удалить объект { listBoxStorages.SelectedItem}?",
+                "Удаление", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
+            {
+                _storage.DelSet(listBoxStorages.SelectedItem.ToString()
+                ?? string.Empty);
+                ReloadObjects();
+            }
         }
         /// <summary>
         /// Добавление объекта в набор
@@ -39,13 +105,23 @@ namespace AirplaneWithRadar
         /// <param name="e"></param>
         private void buttonAdd_Click(object sender, EventArgs e)
         {
+            if (listBoxStorages.SelectedIndex == -1)
+            {
+                return;
+            }
+            var obj = _storage[listBoxStorages.SelectedItem.ToString() ??
+            string.Empty];
+            if (obj == null)
+            {
+                return;
+            }
             AirplaneWithRadarForm form = new();
             if (form.ShowDialog() == DialogResult.OK)
             {
-                if (_airplanes + form.SelectedAirplane != -1)
+                if (obj + form.SelectedAirplane)
                 {
                     MessageBox.Show("Объект добавлен");
-                    pictureBoxCollection.Image = _airplanes.ShowAirplanes();
+                    pictureBoxCollection.Image = obj.ShowAirplanes();
                 }
                 else
                 {
@@ -60,21 +136,32 @@ namespace AirplaneWithRadar
         /// <param name="e"></param>
         private void buttonDelete_Click(object sender, EventArgs e)
         {
+            if (listBoxStorages.SelectedIndex == -1)
+            {
+                return;
+            }
+            var obj = _storage[listBoxStorages.SelectedItem.ToString() ??
+            string.Empty];
+            if (obj == null)
+            {
+                return;
+            }
             if (MessageBox.Show("Удалить объект?", "Удаление",
-                MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.No)
+            MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.No)
             {
                 return;
             }
             int pos = Convert.ToInt32(maskedTextBoxNumber.Text);
-            if (_airplanes - pos != null)
+            if (obj - pos != null)
             {
                 MessageBox.Show("Объект удален");
-                pictureBoxCollection.Image = _airplanes.ShowAirplanes();
+                pictureBoxCollection.Image = obj.ShowAirplanes();
             }
             else
             {
                 MessageBox.Show("Не удалось удалить объект");
             }
+
         }
         /// <summary>
         /// Обновление рисунка по набору
@@ -83,7 +170,18 @@ namespace AirplaneWithRadar
         /// <param name="e"></param>
         private void buttonUpdate_Click(object sender, EventArgs e)
         {
-            pictureBoxCollection.Image = _airplanes.ShowAirplanes();
+            if (listBoxStorages.SelectedIndex == -1)
+            {
+                return;
+            }
+            var obj = _storage[listBoxStorages.SelectedItem.ToString() ??
+            string.Empty];
+            if (obj == null)
+            {
+                return;
+            }
+            pictureBoxCollection.Image = obj.ShowAirplanes();
+
         }
     }
 }
diff --git a/AirplaneWithRadar/AirplaneWithRadar/SetGeneric.cs b/AirplaneWithRadar/AirplaneWithRadar/SetGeneric.cs
index 114ad8b..ba61aa2 100644
--- a/AirplaneWithRadar/AirplaneWithRadar/SetGeneric.cs
+++ b/AirplaneWithRadar/AirplaneWithRadar/SetGeneric.cs
@@ -14,58 +14,51 @@ namespace AirplaneWithRadar.Generics
         where T : class
     {
         /// <summary>
-        /// Массив объектов, которые храним
+        /// Список объектов, которые храним
         /// </summary>
-        private readonly T?[] _places;
+        private readonly List<T?> _places;
         /// <summary>
         /// Количество объектов в массиве
         /// </summary>
-        public int Count => _places.Length;
+        public int Count => _places.Count;
+        /// <summary>
+        /// Максимальное количество объектов в списке
+        /// </summary>
+        private readonly int _maxCount;
         /// <summary>
         /// Конструктор
         /// </summary>
         /// <param name="count"></param>
         public SetGeneric(int count)
         {
-            _places = new T?[count];
+            _maxCount = count;
+            _places = new List<T?>(count);
         }
         /// <summary>
         /// Добавление объекта в набор
         /// </summary>
-        /// <param name="car">Добавляемый самолет</param>
+        /// <param name="airplane">Добавляемый самолет</param>
         /// <returns></returns>
-        public int Insert(T airplane)
+        public bool Insert(T airplane)
         {
-            return Insert(airplane, 0);
+            if (_places.Count == _maxCount)
+            {
+                return false;
+            }
+            Insert(airplane, 0);
+            return true;
         }
         /// <summary>
         /// Добавление объекта в набор на конкретную позицию
         /// </summary>
-        /// <param name="car">Добавляемый автомобиль</param>
+        /// <param name="airplane">Добавляемый самолет</param>
         /// <param name="position">Позиция</param>
         /// <returns></returns>
-        public int Insert(T airplane, int position)
+        public bool Insert(T airplane, int position)
         {
-            int nullIndex = -1, i;
-            if (position < 0 || position >= Count) 
-            {
-                return -1;
-            }
-            for (i = position; i < Count; i++)
-            {
-                if (_places[i] == null)
-                {
-                    nullIndex = i;
-                    break;
-                }
-            }
-            if (nullIndex < 0) return -1;
-            for (i = nullIndex; i > position; i--)
-            {
-                _places[i] = _places[i - 1]; 
-            }
-            _places[position] = airplane;
-            return position;
+            if (!(position >= 0 && position <= Count && _places.Count < _maxCount))  return false;
+            _places.Insert(position, airplane);
+            return true;
         }
         /// <summary>
         /// Удаление объекта из набора с конкретной позиции
@@ -75,7 +68,7 @@ namespace AirplaneWithRadar.Generics
         public bool Remove(int position)
         {
             if (position < 0 || position >= Count) return false;
-            _places[position] = null;
+            _places.RemoveAt(position);
             return true;
         }
         /// <summary>
@@ -83,10 +76,34 @@ namespace AirplaneWithRadar.Generics
         /// </summary>
         /// <param name="position"></param>
         /// <returns></returns>
-        public T? Get(int position)
+        public T? this[int position]
         {
-            if (position < 0 || position >= Count) return null;
-            return _places[position];
+            get
+            {
+                if (position < 0 || position >= Count) return null;
+                return _places[position];
+            }
+            set
+            {
+                if (!(position >= 0 && position < Count && _places.Count < _maxCount)) return;
+                _places.Insert(position, value);
+                return;
+            }
+        }
+        /// <summary>
+        /// Проход по списку
+        /// </summary>
+        /// <returns></returns>
+        public IEnumerable<T?> GetAirplanes(int? maxAirplanes = null)
+        {
+            for (int i = 0; i < _places.Count; ++i)
+            {
+                yield return _places[i];
+                if (maxAirplanes.HasValue && i == maxAirplanes.Value)
+                {
+                    yield break;
+                }
+            }
         }
     }
 }