#include<bits/stdc++.h>
#define rep(i,a,n) for (int i = a;i < n;i++)
using namespace std;

int main() {
    long long n,ans=0; cin >> n;
    rep(i,1,n+1) {
        if(i % 3 == 0 && i % 5 ==0){
            ans += 4;
        }else if(i%3 == 0){
            ans += 2;
        }else if(i % 5 == 0) {
            ans += 2;
        }
    }
    cout << ans << endl;
}