#include <iostream>
#include <cmath>
using namespace std;

int main(){
	double num;
	while( cin >> num ){
		double res=0;
		if( num > 0 ){
			for(double i=0.00001; i<15; i=i+0.00001){
				if( abs(num - i*i*i) <= 0.0001 ){
					res = i;
//					cout << i << " " << num-i*i*i << endl;
				}
			}
			printf("%.1f\n", res);
		}
		if( num < 0 ){
			for(double i=-0.00001; i>-15; i=i-0.00001){
				if( abs(num - i*i*i) <= 0.0001 ){
					res = i;
//					cout << i << " " << num-i*i*i << endl;
				}
			}
			printf("%.1f\n", res);
		}
		if( num == 0 )
			printf("%.1f\n", res);
		
	}
	
	return 0;
}