diff --git a/MotorPlant/MotorPlantFileImplement/Implements/ShopStorage .cs b/MotorPlant/MotorPlantFileImplement/Implements/ShopStorage .cs
index aefb9ca..29ae922 100644
--- a/MotorPlant/MotorPlantFileImplement/Implements/ShopStorage .cs	
+++ b/MotorPlant/MotorPlantFileImplement/Implements/ShopStorage .cs	
@@ -74,16 +74,13 @@ namespace MotorPlantFileImplement.Implements
 			}
 			return null;
 		}
-		public bool CheckAvailability(int engineId, int count)
-		{
-			int store = _source.Shops.Select(x => x.ShopEngines.Select(y => (y.Value.Item1.Id == engineId ? y.Value.Item2 : 0)).Sum()).Sum();
-			return store >= count;
-		}
+
 		public bool SellEngines(IEngineModel model, int count)
 		{
-			var dres = _source.Engines.FirstOrDefault(x => x.Id == model.Id);
+			var eng = _source.Engines.FirstOrDefault(x => x.Id == model.Id);
+            int store = _source.Shops.SelectMany(x => x.ShopEngines).Sum(y => y.Key == model.Id ? y.Value.Item2 : 0);
 
-			if (dres == null || !CheckAvailability(model.Id, count))
+            if (eng == null || store < count)
 			{
 				return false;
 			}
@@ -92,7 +89,7 @@ namespace MotorPlantFileImplement.Implements
 			{
 				var shop = _source.Shops[i];
 				var engines = shop.ShopEngines;
-				foreach (var engine in engines.Where(x => x.Value.Item1.Id == dres.Id))
+				foreach (var engine in engines.Where(x => x.Value.Item1.Id == eng.Id))
 				{
 					var selling = Math.Min(engine.Value.Item2, count);
 					engines[engine.Value.Item1.Id] = (engine.Value.Item1, engine.Value.Item2 - selling);