import java.math.BigDecimal;
import java.util.*;
public class Main {
    public static void main(final String[] args) {
        final Scanner sc = new Scanner(System.in);
        final int n = sc.nextInt();
        final int k = sc.nextInt();
        Double d = 0.0;
        for (int i = 1; i <= n; i++) {
            double temp = (1.0d / n);
            int t = i;
            while (t < k) {
                t *= 2;
                temp /= 2;
            }
            d += temp;
        }
        System.out.print(BigDecimal.valueOf(d).toPlainString());
    }
}
/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