import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;


public class Main{

	public static void main(String[] args) throws IOException {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer in=new StringTokenizer(br.readLine());
        int N =Integer.parseInt(in.nextToken());
        int K =Integer.parseInt(in.nextToken());
        in = null;
        br = null;
        double ans = 0.0;

        for (int i = 1; i <= N; i++) {
        	int tmp = i;
        	double d = 1.0 / N;
        	while (K > tmp) {
        		tmp *= 2;
        		d /= 2;
        	}
        	ans += d;
        }

        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