#include <stdio.h>
int hermite( int n, int x );
void main()
{
int n,x,s;
scanf("%d%d",&n,&x);
s = hermite( n, x );
printf("%d/n",s);
}
int hermite( int n, int x )
{
if ( n<=0 )
return(1);
else if ( n==1 )
return(2*x);
else
return( 2*x*hermite(n-1,x)-2*(n-1)*hermite(n-2, x) );
}
