//#pragma GCC optimize ("O3")
//#pragma GCC target ("sse4")

#include <iostream>

using namespace std;

#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
  enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
~debug() { cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
sim dor(const c&) { ris; }
#endif
};
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "


// CHECK THE LIMITS
typedef long long ll;

const int MOD = 1000000007;
const ll INFLL = 1e18;
const int INF = 1e9;
const int NMAX = 1000001;

int gcd(int a, int b) {
  return b ? gcd(b, a%b) : a;
} 

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
	int n;
	cin >> n;
	
	int  k =0;
	ll s= 0;
	int i = 1;
	while(k < n)
	{
		if(i % 3 != 0 && i % 5 != 0)
			s+=i;
		i++;
		k++;
	}
	cout << s;


    return 0;
}