import java.util.*;

class Main{
    public static void main(String[] args) {       
        Scanner stdIn = new Scanner(System.in);
        int n = stdIn.nextInt();
        int k = stdIn.nextInt();
        double ans = 0;
        for(int i = 1; i <= n ; i++){
            double p = 1;
            int x = i;
            while(x < k){
                p /= 2;
                x *= 2;
            }
            ans += p/n;
        }
        System.out.println(ans);
   }
}

/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