#pragma GCC optimize("O2")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
using namespace std;
using ll = long long;
//using arr = array;
using pi = pair<ll, ll>;
using vi = vector<ll>;
using vpi = vector<pi>;
using ld = long double;
const int maxn = 1<<17, mod = 1e9 + 7, lg = 19;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	ll n, ans = 0;
	cin >> n;
	for(int i = 1; i <= n; i++)
		if((i%5)&&(i%3)) ans += i;
	cout << ans;
	return 0;
}
