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

int main(){
    long long int N, cnt_15, sub, cnt = 0, i;

    cin >> N;
    cnt_15 = N/15;
    sub = N%15;
    cnt = 16*cnt_15;

    for(i = 1; i <= sub; i++){
        if(i%3 == 0 || i%5 == 0){
            cnt += 2;
        }
    }

    cout << cnt << endl;

    return 0;
}