#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int,int>;
 
int main(){
    int n;
    cin >> n;
    ll ans = 0;
    rep(i, n+1){
        if(i%5 != 0 && i%3 != 0){
            ans += i;
        }
    }
    cout << ans << endl;
    return 0;
}