N, K = map(int, input().split())

# 何回2をかけると超えるか。
def func1(i, k):
    ans = 0
    num = i
    end = False
    if num >= k:
        return 0
    while(not end):
        ans += 1
        num *= 2
        if num >= k:
            end = True
            break
    return ans


ans = 0
for initial_score in range(1, N+1):
    ans += (1/N) * (1/2) ** func1(initial_score, K)
print(ans) N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K def func1(i, k):
    ans = 0
    num = i
    end = False
    if num >= k:
        return 0
    while(not end):
        ans += 1
        num *= 2
        if num >= k:
            end = True
            break
    return ans func1 ans = 0 ans 0 num = i num i end = False end False if num >= k:
        return 0
     num >= k num k return 0 0 while(not end):
        ans += 1
        num *= 2
        if num >= k:
            end = True
            break
     not end end ans += 1 ans 1 num *= 2 num 2 if num >= k:
            end = True
            break
     num >= k num k end = True end True break return ans ans i i k k ans = 0 ans 0 for initial_score in range(1, N+1):
    ans += (1/N) * (1/2) ** func1(initial_score, K) initial_score range(1, N+1) range 1 N+1 N 1 ans += (1/N) * (1/2) ** func1(initial_score, K) ans (1/N) * (1/2) ** func1(initial_score, K) 1/N 1 N (1/2) ** func1(initial_score, K) 1/2 1 2 func1(initial_score, K) func1 initial_score K print(ans) print ans def func1(i, k):
    ans = 0
    num = i
    end = False
    if num >= k:
        return 0
    while(not end):
        ans += 1
        num *= 2
        if num >= k:
            end = True
            break
    return ans def func1(i, k):
    ans = 0
    num = i
    end = False
    if num >= k:
        return 0
    while(not end):
        ans += 1
        num *= 2
        if num >= k:
            end = True
            break
    return ans func1 ans += (1/N) * (1/2) ** func1(initial_score, K) (1/N) * (1/2) ** func1(initial_score, K) ans ans = 0 0 ans K = map(int, input().split()) map(int, input().split()) K N, K = map(int, input().split()) map(int, input().split()) N
N, K = map(int, input().split())

# 何回2をかけると超えるか。
def func1(i, k):
    ans = 0
    num = i
    end = False
    if num >= k:
        return 0
    while(not end):
        ans += 1
        num *= 2
        if num >= k:
            end = True
            break
    return ans


ans = 0
for initial_score in range(1, N+1):
    ans += (1/N) * (1/2) ** func1(initial_score, K)
print(ans)