import java.util.Scanner;
public class Staircases {
      public static void main(String... args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        System.out.println(find_Q(N, N));
    }

      static int find_Q(int X, int Y) {
         int U = X-1;
         if(Y<X) {
         U = Y;
         if(Y == 0 || Y ==1)
         return 1;
         }
         if(Y<=1)
         return 0;
         int A = 0;
         for(int i = U; i > 0; i--)
          A += find_Q(i, Y-i);
         return A;
          }
}

Use bottom-up approach, calling function and return rakes huge amount of time