import java.util.*;

public class Main
{
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        final int n = sc.nextInt();
        final int k = sc.nextInt();

        double sum = 0;
        final double base = 0.5;
        final double base2 = 1/(double)n;
        for (int deme = 1;deme <= n;++deme)
        {
            int nn = 0;
            int s = deme;
            while (s < k)
            {
                s *= 2;
                ++nn;
            }
            sum += base2*Math.pow(base,nn);
        }
        System.out.println(sum);
        sc.close();
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz