import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int K = sc.nextInt();

        double count = 0;

        for(int i=1; i <= N; i++){
            double tmp02 = 1;

            for(int n=i; n < K; n=n*2){
                tmp02 = tmp02 * 0.5;
            }
            count = count + tmp02 / N;
        }
        System.out.print(count);
    }

}
/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