diff --git a/src/main/java/com/example/demo/DemoApplication.java b/src/main/java/com/example/demo/DemoApplication.java
index e03ec75..650c5a9 100644
--- a/src/main/java/com/example/demo/DemoApplication.java
+++ b/src/main/java/com/example/demo/DemoApplication.java
@@ -2,11 +2,63 @@ package com.example.demo;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
 
 @SpringBootApplication
+@RestController
 public class DemoApplication {
 
 	public static void main(String[] args) {
 		SpringApplication.run(DemoApplication.class, args);
 	}
+
+
+	@GetMapping("/hello")
+	public String hello(@RequestParam(value = "name", defaultValue = "World") String name) {
+		return String.format("Hello %s!", name);
+	}
+
+	@GetMapping("/calc1")
+	public Integer calc1(@RequestParam int val1,
+						 @RequestParam int val2) {
+		return val1 * val2;
+	}
+
+	@GetMapping("/calc2")
+	public Integer calc2(@RequestParam int val1,
+						 @RequestParam int val2) {
+		if (val2==0){
+			return 1;
+		}
+		int c=1;
+		for (int i=0; i<val2; i++) {
+			c = c * val1;
+		}
+		return c;
+	}
+
+	@GetMapping("/calc3")
+	public Integer calc3(@RequestParam int val1) {
+		if (val1==0){
+			return 1;
+		}
+		int c=1;
+		for (int i=1; i<=val1; i++) {
+			c = c * i;
+		}
+		return c;
+	}
+
+	@GetMapping("/calc4")
+	public Integer calc4(@RequestParam int val1) {
+		if (val1 <= 1) {
+			return 0;
+		} else if (val1 == 2) {
+			return 1;
+		} else {
+			return calc4(val1 - 1) + calc4(val1 - 2);
+		}
+	}
 }