import java.util.Scanner; public class Main {     public static void main(String[] args) {         Scanner in = new Scanner(System.in);         int n = in.nextInt();         System.out.println(getall(n));     }     public static int getold(int n){         if (n<3) {             return 0;         }if (n==3) {             return 1;         }         else {             return getall(n-2);         }     }     public static int getall(int n){         if (n<=3) {             return 1;         }else {             return getall(n-1)+getold(n-1);         }     } }