#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp> // Common file
//#include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update
 
using namespace std;
//using namespace __gnu_pbds;
//typedef tree< pair<int, int>, null_type, less<pair<int, int>>, rb_tree_tag, tree_order_statistics_node_update>
//ordered_set;
int dx[] = {0, 1, 0, -1};
int dy[] = {-1, 0, 1, 0};
#define X first
#define Y second
#define int long long int 
const int N = (int)1e6 + 10;
const int MOD = (int) 1e9 + 7;


void solve(){
    int n; cin >> n;
    int sum = 0;
    for(int i = 1; i <= n; ++i){
        if( (i%3) != 0 and (i%5) != 0){
            sum += i;
        }
    }
    cout << sum << '\n';
}

int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr); 
    //int t; cin >> t;
    //while(t--)
        solve();
    return 0;
}
/*
Sample inp
*/