#include<stdio.h>
#include<conio.h>
void main()
{   char myMun=0;
  
    while(1)
    {   
        char myNum;
        myNum=getch();
        


        if(myNum>='0'&&myNum<='9')
        {
            putchar(myNum);
        }   
        else if (myNum=='\r')
        {   
            break;
        }
        else if(myNum=='\b')
        {
             putchar(myNum);
        }
        else
        {
            myNum=0;
        }
    }
}

else if(myNum=='\b')
        {
             putchar(myNum);
             putchar(' ');
             putchar(myNum);
        }