import sys

def main():
    input = sys.stdin.readline
    N, K = map(int, input().split())

    ans = 0
    for i in range(1, N+1):
        cnt = 0
        while i * 2**cnt < K:
            cnt += 1

        ans += 1 / N * (0.5)**cnt

    return ans

if __name__ == '__main__':
    print(main()) import sys sys def main():
    input = sys.stdin.readline
    N, K = map(int, input().split())

    ans = 0
    for i in range(1, N+1):
        cnt = 0
        while i * 2**cnt < K:
            cnt += 1

        ans += 1 / N * (0.5)**cnt

    return ans main input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K ans = 0 ans 0 for i in range(1, N+1):
        cnt = 0
        while i * 2**cnt < K:
            cnt += 1

        ans += 1 / N * (0.5)**cnt

     i range(1, N+1) range 1 N+1 N 1 cnt = 0 cnt 0 while i * 2**cnt < K:
            cnt += 1

         i * 2**cnt < K i * 2**cnt i 2**cnt 2 cnt K cnt += 1 cnt 1 ans += 1 / N * (0.5)**cnt ans 1 / N * (0.5)**cnt 1 / N 1 N (0.5)**cnt 0.5 cnt return ans ans if __name__ == '__main__':
    print(main()) __name__ == '__main__' __name__ '__main__' print(main()) print main() main def main():
    input = sys.stdin.readline
    N, K = map(int, input().split())

    ans = 0
    for i in range(1, N+1):
        cnt = 0
        while i * 2**cnt < K:
            cnt += 1

        ans += 1 / N * (0.5)**cnt

    return ans def main():
    input = sys.stdin.readline
    N, K = map(int, input().split())

    ans = 0
    for i in range(1, N+1):
        cnt = 0
        while i * 2**cnt < K:
            cnt += 1

        ans += 1 / N * (0.5)**cnt

    return ans main
import sys

def main():
    input = sys.stdin.readline
    N, K = map(int, input().split())

    ans = 0
    for i in range(1, N+1):
        cnt = 0
        while i * 2**cnt < K:
            cnt += 1

        ans += 1 / N * (0.5)**cnt

    return ans

if __name__ == '__main__':
    print(main())