#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sstream>
#include <iostream>
#include <math.h>
#include <time.h>
#include <unistd.h>
#include <algorithm>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <set>
#include <string>
 
#ifndef ONLINE_JUDGE
	#define DEBUG(x) cout << '>' << #x << ':' << x << endl;
#else
	#define DEBUG(x) do {} while(0);
#endif
 
#define pb push_back
#define mp make_pair
#define ALL(x) (x).begin(), (x).end()
#define PER(i, N) for(int (i) = (N)-1; (i) >= 0; (i)--)
#define REP(i, N) for(int (i) = 0; (i) < (int)(N); (i)++)
 
using namespace std;
typedef long long ll;
inline bool EQ(double a, double b) { return fabs(a-b) < 1e-9; }

template <typename T, typename U> std::istream&operator>>(std::istream&i, pair<T,U>&p) {i >> p.x >> p.y; return i;}
template<typename T>std::istream&operator>>(std::istream&i,vector<T>&t) {for(auto&v:t){i>>v;}return i;}
template <typename T, typename U> std::ostream&operator<<(std::ostream&o, const pair<T,U>&p) {o << p.x << ' ' << p.y; return o;}
template<typename T>std::ostream&operator<<(std::ostream&o,const vector<T>&t) {if(t.empty())o<<'\n';for(size_t i=0;i<t.size();++i){o<<t[i]<<" \n"[i == t.size()-1];}return o;}
template<typename T> using minheap = priority_queue<T, vector<T>, greater<T>>;
template<typename T> using maxheap = priority_queue<T, vector<T>, less<T>>;
template<typename T> T gcd(T a,T b) { if (a<b) swap(a,b); return b?gcd(b,a%b):a; }

int n,m;

void solve(istream& cin, ostream& cout) {
	cin >> n;
	ll ans = 0;
	REP(i, n) {
		if((i+1) % 3 != 0 && (i+1) % 5 != 0) {
			ans += i+1;
		}
	}
	cout << ans <<endl;
}


int main() {
    ios_base::sync_with_stdio(false);
	cin.tie(nullptr); cout.tie(nullptr);
	solve(cin, cout);
	/*
	{
		istringstream instr("2\n2\n14");
		solve(instr, cout);
	}
 */
	return 0;
}
