#include<iostream>

using namespace std;
#include<string>

main()
{
      double CR,input;
      CR = 0;
      int x,y,z;
      
      cout << "Input: " << endl;
      cin >> input;
      
      while (CR*CR*CR <= input)
        ++CR;
        
       --CR;
        
       while (CR*CR*CR <= input)
          CR += 0.1;
          
        CR -= 0.1;
       
       while (CR*CR*CR <= input)
          CR += 0.01;
          
        CR -= 0.01;
         
        while (CR*CR*CR <= input)
          CR += 0.001;
           
          CR -= .001;
       
       
       double CRFalse=CR;
       while (CRFalse*CRFalse*CRFalse <= input)
          CRFalse += 0.0001;
           
          CRFalse -= .0001;  
       if((int)(CRFalse*1000)%10>0)
          CR+=.001;
        CR*=1.000;
       
        if((int)(CRFalse*10)%10==0)
        cout << CR << ".0";
        
        if((int)(CRFalse*100)%10==0)
        cout << "0";
        
        if((int)(CRFalse*1000)%10==0)
        cout << "0" << endl;
        
        if( ((int)(CRFalse*1000)%10!=0) && ((int)(CRFalse*100)%10!=0) && ((int)(CRFalse*10)%10!=0) )   
        cout << CR << endl;
        
while (1)
{}

}