#include <iostream>
using namespace std;

int main()
{
    long long N;
    cin >> N;
    //2*(3の倍数+5の倍数-2*15の倍数) + 4*15の倍数
    long long tmp3 = N / 3;
    long long tmp5 = N / 5;
    long long tmp15 = N / 15;
    cout << 2 * (tmp3 + tmp5 - 2 * tmp15) + 4 * tmp15 << endl;
    return 0;
}