#include <bits/stdc++.h>
using namespace std;

#define put(i) cout << i << endl

int main() {
    long long n, ans = 0; cin >> n;
    for (int i = 1; i <= n; ++i) {
        if (i%3==0) ans += 2;
        if (i%5==0) ans += 2;
    }
    put(ans);
}