/* -*- coding: utf-8 -*-
 *
 * 1229.cc:  No.1229 ラグビーの得点パターン - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

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

  int c = 0;
  for (int x = 0; x * 5 <= n; x++) {
    int m = n - x * 5;
    for (int y = 0; y * 2 <= m && y <= x; y++)
      if ((m - y * 2) % 3 == 0) c++;
  }

  printf("%d\n", c);
  return 0;
}