using System;

namespace yukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] s = Console.ReadLine().Split(' ');
            double a = double.Parse(s[0]);
            double b = double.Parse(s[1]);
            double ans = 0;

            a= Math.Pow(2,a);
            b = Math.Pow(2,b);
            if (b < a)
            {
                ans = a / b;
            }
            

            Console.WriteLine(ans);
        }
    }
}