#include <cstdio>
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <set>

using namespace std;
typedef long long ll;
ll mod = 1000000007;

int main() {
    ll n; cin >> n;
    ll ans = 0;
    for (int i = 1; i <= n; i++) {
        if (i % 3 != 0 && i % 5 != 0) ans += i;
    }
    cout << ans << "\n";
}