#include<stdio.h>
int main()
{
int b,p;
freopen ("fructe.in","r",stdin);
freopen ("fructe.out","w",stdout);
scanf ("%d%d",&b,&p);         
if(p==0 && b<2 || p<2 && b==0 || p==0 && b==0)
   printf("imposibil");
else
  if(p==b)
     {if(b%2==1)
	printf("0");
      if(b%2==0)
	printf("1");}
else
   if(p<b)
   {if(p%2==0)
      printf("0");
    if(p%2==1)
      printf("1");}
else
   if(p>b)
   {if(b%2==0)
      printf("1");
    if(b%2==1)
      printf("0");}

return 0;
}