#include<iostream>
#include<string>
#include<vector>
#include<utility>
#include<algorithm>
#include<map>
#include<cstdlib>
#include<cmath>
using namespace std;
using ll =long long;
int main() {
	ll N;
	ll sum=0;
	cin >> N;
	for (int i = 1; i <= N; i++) {
		if (i % 5 != 0&& i % 3 != 0) {
 
 
			sum += i;
		}
	}
	cout << sum;
}