#include <iostream>
using namespace std;
int main(void){
    int n;
    cin >> n;
    int64_t sum = 0;
    for (int i = 1; i <= n; i++){
        if(i % 3 == 0)
            continue;
        if(i % 5 == 0)
            continue;
        sum += i;
        }
    cout << sum << endl;
}
