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

pre = [0] * (2 * K + 1)
pre[0] = 1
for i in range(N):
    dp = [0] * (2 * K + 1)
    for j in range(2 * K + 1):
        dp[j] |= pre[j]
        if j - A[i] >= 0:
            dp[j] |= pre[j - A[i]]
    dp, pre = pre, dp

ans = 0
for i in range(N):
    if pre[K] and not pre[K + A[i]]:
        ans += 1

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