//OPTIMIZATONS
#pragma GCC optimize("02")
//CODE
#include<bits/stdc++.h>
// uncomment the below code to use int as long long
#define int long long
// uncomment the below code to use float as double
//#define float double
#define endl "\n"
#define debug cout<<"Good uptill here"<<endl<<flush;
#define deb(x) cout<<#x<<":"<<x<<endl<<flush;

using namespace std;

int32_t main(){
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	//CODE FOR SPECIFIED INPUT AND OUTPUT
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
	int n;
	cin>>n;
	int ans = 0;
	for(int i=1;i<=n;i++){
		if(i%3!=0 && i%5!=0) ans += i;
	}
	cout<<ans<<endl;
	return 0;
}

