#include <bits/stdc++.h>

#define rep2(x,fr,to) for(int (x)=(fr);(x)<(to);(x)++)
#define rep(x,to) for(int (x)=0;(x)<(to);(x)++)
#define repr(x,fr,to) for(int (x)=(fr);(x)>=(to);(x)--)
#define all(c) (c).begin(),(c).end()
#define sz(v) (int)(v).size()

using namespace std;
typedef long long ll; typedef vector<int> VI; typedef pair<int,int> pii;
typedef vector<ll> VL; const int MD = (int)1e9 + 7;
void dbg(){ cerr << "\n"; } template <typename T,typename ...T2> void dbg(const T& fst, const T2&...rst){ cerr << fst << ": "; dbg(rst...); }

int main()
{
	//cin.tie(0); ios_base::sync_with_stdio(false);
	int n; ll ans =0;
	cin >>n;
	
	rep2(i, 1, n+1){
		if(i%3==0 || i%5==0) continue;
		ans +=i;
	}
	cout <<ans <<"\n";
	return 0;
}
