#include <bits/stdc++.h>
#include <iostream>
#include <queue>
#include <vector>
#include <string>
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define repp(i,n,m) for (int i = m; i < (n); ++i)
#define repl(i,n) for (long long i = 0; i < (n); ++i)
#define reppl(i,n,m) for (int i = m; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;
using PL = pair<long long, long long>;
const int INF = 1001001007;
const int mod = 1000000007;

int main(){
    int n; cin >> n;
    ll ans = 0;
    repp(i,n+1,1){
        if (i % 3 != 0 && i % 5 != 0) ans += i; 
    }
    cout << ans << endl;
}