import java.util.*;

class Main{
    final static long mod = 1000000007;
    //
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int k = sc.nextInt();
        double prob = 0;
        for(int i = 1; i <= n; i++){
            int cnt = 0;
            int num = i;
            while(num < k){
                num *= 2;
                cnt++;
            }
            prob += 1.0 / Math.pow(2.0, cnt);
        }
        System.out.println(prob / n);
    }
    
}
/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