FunHexadecimal

import java.util.Scanner;
public class FunHexadecimal{
  public static String letShift(String str , int n){
     Scanner in = new Scanner(System.in);
    int time;
    switch(n)
    {
      case 0 : System.out.println("Why you don't play?");
      break;
      case 1 : System.out.println("Please input time you wand to shift");
               time = in.nextInt();
               for(int i = 1 ; i <= time ; i++)
               {
                 str =  0 + str;
               }
               //return str.substring(0,str.length()-time);
               break;
     case -1 : System.out.println("Please input time you wand to shift");
               time = in.nextInt();
               for(int i = 1 ; i <= time ; i++)
               {
                 str =   str + 0;
               }
               //return str.substring(time,str.length());
               break;
    }
    return str;
  }
  public static String winWin(int x){
    String s = "" + x;
     if(x == 15) s = "F";
     if(x == 14) s = "E";
     if(x == 13) s = "D";
     if(x == 12) s = "C";
     if(x == 11) s = "B";
     if(x == 10) s = "A";
     return s;
  }
  public static int funPower(int a , int b){
    int sum = 1;
    for(int i = 1 ; i <=b ; i++)
    {
      sum = sum*a;
    }
    return sum;
  }
  
  public static void main(String[]args){
    Scanner in = new Scanner(System.in);
    int hexin = 0,i;
    String hex = in.nextLine() , s = "";
    int lastdi = 0;
    String x = "";
    for(i = hex.length() - 1 ; i>=0 ; i-- )
    {
      s = ""+hex.charAt(i);
     if(hex.charAt(i)== 'A') s = "10";
     if(hex.charAt(i)== 'B') s = "11";
     if(hex.charAt(i)== 'C') s = "12";
     if(hex.charAt(i)== 'D') s = "13";
     if(hex.charAt(i)== 'E') s = "14";
     if(hex.charAt(i)== 'F') s = "15";
     hexin = Integer.parseInt(s);
     while(hexin > 0)
     {
       lastdi = hexin % 2;
       x = x + lastdi;
       hexin = hexin / 2;
     }
    }
    System.out.println(x);
     System.out.println("Do you want to shift?\nIf yes and shift right say 1\nIf no say 0\nIf yes and shift left say -1");
    int shift = in.nextInt();
    x = letShift(x, shift);
    int div = x.length()%4;
    if(div != 0)
    {
      for(i = 1 ; i <= 4-div; i++)
      {
        x = 0 + x;
      }
    }
    System.out.println(x);
    int j,bin,power,p =3,sum=0;
    String boy = "";
    for(i = 0 ; i+3 <= x.length(); i+=4)
    {
      for(j=0; j <=3 ;j++,p--)
      { 
        power = funPower(2,p);
        bin = Integer.parseInt(x.substring(i+j,i+j+1));
        sum = sum + (bin*power);
      }
      boy = boy + winWin(sum);
    }
    System.out.println(boy);
    
    
  }
}