import java.util.*;

 class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long K = sc.nextLong();
        double p=0;
        
        for(int i=1;i<=N;i++) {
        	double k = 1.0/N;
        	for(int j=i;j<K;j=j*2){
        		k=k/2;
        	}
        	p=p+k;
        }
        System.out.println(p);
    }

}
/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