//WAかTLE
#include <iostream>
using namespace std;

int n;

int gcd(int a, int b) {
	if (b == 0) return a;
	return gcd(b, a % b);
}

int dfs(int num, long long used) {
	if (num > n) {
		return 0;
	}
	
	int ret = dfs(num + 1, used);	//数字numを使わない場合
	int i;
	
	for (i = 2; i < num; i++) {
		if ((used >> i) % 2 == 1 && gcd(i, num) >= 2) {
			break;
		}
	}
	if (i == num) {
		//数字numを使う場合
		ret = max(ret, num + dfs(num + 1, used + (1LL << num)));
	}
	return ret;
}

signed main() {
	cin >> n;
	cout << dfs(2, 0) << endl;
	return 0;
}