#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    int64_t n;
    cin >> n;
    cout << (n / 3 * 2 + n / 5 * 2) << endl;
    return 0;
}