from sys import stdin


def main():
    input = lambda: stdin.readline()[:-1]
    N, K = map(int, input().split())
    A = list(map(int, input().split()))

    ans = set()
    for mask in range(1, 1 << N):
        nums = []
        for i in range(N):
            if mask & 1 << i:
                nums.append(A[i])
        if sum(nums) == K:
            ans.add(tuple(nums))

    if ans:
        print(len(ans))
    else:
        print(-1)


main()