#include<bits/stdc++.h>
using namespace std;
long long n;
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin >> n;
	long long l = 1, r = n;
	while (l <= r) {
		long double mid = (l + r) / 2.0;
		if (floor(pow(mid, 3)) == n) {
			cout << mid;
			return 0;
		}
		else if (floor(pow(mid, 3)) > n) r = mid - 1;
		else l = mid + 1;
	}
	return 0;
}