//WA
#include <stdio.h>
int main()
{
	double pp, t, arr[100];
	int i, n;
	while( scanf("%d%lf",&n,&t) && n )
	{
		arr[0] = 1.0;
		for( i = 1; i <= n; i++ )
		{
			pp = 1.0 / ( arr[i-1] + 1.0 );
			if( t >= pp )
			{
				arr[i] = 1.0 + t;
				arr[i] *= arr[i-1];
			}
			else
			{
				arr[i] = ( pp - t ) / ( 1.0 - t ) + ( 1.0 - pp ) / ( 1.0 - t ) * ( 1.0 + pp );
				arr[i] *= arr[i-1];
			}
		}
		printf("%.3lf\n",(arr[n]));
	}
	return 0;
}