#include<stdio.h>
void main()
{ int a=1,b=0;
  switch(a)
  {case 1:  switch(b)
                 { case 0:printf("**0**\n");break;
                   case 1:printf("**1**\n");break;
                 }
    case 2:  printf("**2**\n");break;
  }
}