#include<bits/stdc++.h>
using namespace std;
//#pragma GCC target ("avx")
#pragma GCC optimization ("Ofast")
#pragma GCC optimization ("unroll-loops")
#define int long long
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,n) for(int i=1;i<n;i++)
#define all(v) v.begin(),v.end()
#define P pair<int,int>
#define siz(s) (int)s.size()

template<class T> inline bool chmin(T &a, T b) {
	if(a>b){a=b;return true;}
	return false;
}
template<class T> inline bool chmax(T &a, T b) {
	if(a<b){a=b;return true;}
	return false;
}
template<class T> inline int getidx(vector<T> &v, T a) {
	return lower_bound(all(v), a) - v.begin();
}

constexpr int mod=998244353;
constexpr int inf=3e18;


signed main(){
	cin.tie(0);ios::sync_with_stdio(false);
	int N;cin>>N;
	int sum=0;
	REP(i,N+1){
		if(i%3&&i%5)sum+=i;
	}
	cout<<sum<<"\n";
}
