#include<iostream>

using namespace std;

int main()
{
	long long n;
	cin >> n;
	long long left = 1;
	long long right = 100000;
	long long mid;
	while (true)
	{
		mid = (left + right) / 2;
		if (mid == left)
		{
			cout << left;
			break;
		}
		if (mid*mid*mid >= n)
			right = mid;
		else
			left = mid;
	}
	
}