/* -*- coding: utf-8 -*-
 *
 * 2862.cc:  No.2862 NOT FOUND 404 - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 100000;

/* typedef */

/* global variables */

char s[MAX_N + 4];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d%s", &n, s);

  for (int i = 0; i + 2 < n; i++)
    if (s[i] == '4' && s[i + 1] == '0' && s[i + 2] == '4') {
      puts("Found");
      return 0;
    }

  puts("NotFound");
  return 0;
}