#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "string"
#include "map"
#include "unordered_map"
#include "unordered_set"
#include "iomanip"
#include "cmath"
#include "random"
#include "bitset"
#include "cstdio"
#include "numeric"
#include "cassert"
#include "ctime"

using namespace std;

constexpr long long int MOD = 1000000007;
//constexpr int MOD = 1000000007;
//constexpr int MOD = 998244353;
//constexpr long long int MOD = 998244353;
constexpr long double EPS = 1e-8;

long long int N, M, K, L, R, H, W;
//int N, M, K, L, R, H, W;


int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> N;
	for (int i = 1; i <= N; i++) {
		if (i % 3 == 0)continue;
		if (i % 5 == 0)continue;
		M += i;
	}
	cout << M << endl;
}