#include <iostream>
using namespace std;
using ll = long long;

int main() {
    int n; cin >> n;
    ll cnt = 0;
    for(int i = 1; i <= n; ++i) {
        if(i % 3 == 0) cnt += 2;
        if(i % 5 == 0) cnt += 2;
    }
    cout << cnt << endl;
    return 0;
}