#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <vector>
#include <set>
#include <queue>
#include <map>
#include <string>

#define rep(i, a, b) for ( int i = (a); i < (b); i++ )
#define per(i, a, b) for ( int i = (b)-1; i >= (a); i--)
#define pb push_back
#define mp make_pair
#define bg begin()
#define en end()
#define all(v) (v).begin(), (v).end()
#define sz(v) (int)(v).size()


using namespace std;

typedef long long ll;

static const long long MOD = 1000000007;

ll ans;

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

    cout << ans << endl;

	return 0;
}
