1 public class MainClass
 2 
 3 {
 4 
 5 public static void Main()
 6 
 7 {
 8 
 9 Console.WriteLine(Foo(30));
10 
11 }
12 
13 public static int Foo(int i)
14 
15 {
16 
17 if (i <= 0)
18 
19 return 0;
20 
21 else if(i > 0 && i <= 2)
22 
23 return 1;
24 
25 else return Foo(i -1) + Foo(i - 2);
26 
27 }
28 
29 }