#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;
}