from heapq import heappush,heappop,heapify

def cookies(k, A): heapify(A) iterations=0

while len(A)>1 and A[0]<k and (A[1]<k or A[2]<k):
    a=heappop(A)
    b=heappop(A)
    heappush(A,a+2*b)
    iterations+=1

if len(A)==1:
    if A[0] >= k:
        return iterations
    else:
        return -1
else:
    if A[0] >= k:
        return iterations
    else:
        return iterations + 1

if name == 'main': fptr = open(os.environ['OUTPUT_PATH'], 'w')

first_multiple_input = input().rstrip().split()

n = int(first_multiple_input[0])

k = int(first_multiple_input[1])

A = list(map(int, input().rstrip().split()))

result = cookies(k, A)

fptr.write(str(result) + '\n')

fptr.close()