/*
!لَا أَبْرَحُ حَتَّىٰ أَبْلُغَ
فَصَبْرٌ جَمِيلٌ
*/
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#define endl                         '\n'	
#define Ceil(x,y)             ((x+y-1)/y)
#define sz(s)               (int)s.size()
#define RT(x)           return cout<<x,0;
#define mem(x,y)    memset(x,y,sizeof(x))
#define all(v) ((v).begin()), ((v).end())
#define vi                    vector<int>
#define Tesla              file();
#define fr(x,y) for(int x=0; x<(y); ++x)
const double PI = acos(-1), EPS = 1e-7;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int dr[] { -1, -1, 0, 1, 1, 1, 0, -1 };
const int dc[] { 0, 1, 1, 1, 0, -1, -1, -1 };
ll gcd(ll x, ll y) { return (!y) ? x : gcd(y, x%y); }
ll lcm(ll x, ll y) { return ((x / gcd(x, y))*y); }
ll mod = 998244353;
ll power(ll x, ll y)
{
	if (y == 0)return 1;
	if (y == 1)return x;
	ll r = power(x, y / 2) % mod;
	return r%mod*r%mod*power(x, y % 2) % mod;
}
void file() {
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif  !ONLINEJUDGE
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

}

int main()
{
	Tesla
		int n; cin >> n;
	ll ans = 0;
	fr(i, n + 1)
	{
		if (i % 3 == 0 || i % 5 == 0)
			continue;
		ans += i;
	}
	cout << ans;
}