#include <iostream>
using namespace std;
typedef long long ll;

int main(){
	int n;
	cin >> n;
	ll sum = 0;
	for(int i = 1; i <= n; i++){
		if(i % 5 != 0 and i % 3 != 0){
			sum += i;
		}
	}
	cout << sum;
   return 0;
}