#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define rrep2(ri,x,n) for(int ri = (int)(n-1); ri >= (int)(x); ri--)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(x) x.begin(), x.end()
using ll = long long;
using namespace std;

int main(){
  int n;
  cin >> n;
  if(n == 0){
    cout << 1 << endl;
    return 0;
  }
  int ans = 0;
  rep(i, n){
    if(i*5 > n) break;
    rep(j, i+1){
      int now = i*5+j*2;
      if(now > n) break;
      if((n - now) % 3 == 0) ans++;
    }
  }
  cout << ans << endl;
  return 0;
}