#include <iostream>
#include <map>
#include <set>
#include <utility>
#include <numeric> 
#include <bits/stdc++.h>
typedef long long ll;
typedef std::pair<std::pair<int,int>,int>pi;
using namespace std;

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