#include <bits/stdc++.h>

using namespace std;

using ll = long long;

constexpr char newl = '\n';

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    int ans = 0;
    for (int i = 0; i <= n / 5; i++) {
        for (int j = 0; j <= i; j++) {
            int tmp = n - i * 5 - j * 2;
            if (tmp < 0) continue;
            if (tmp % 3 == 0) ++ans;
        }
    }
    cout << ans << newl;

    return 0;
}