#include <iostream>
using namespace std;

int main()
{
    int n;
    cin >> n;
    long long int count = 0;

    for (int i = 0; i < n; i++) {
        if (i % 15 == 0 || i % 5 == 0 || i % 3 == 0)
            continue;
        else 
            count += i; 
    }

    cout << count << endl;
    
    return 0;
}