n, k = map(int, input().split())
A = list(map(int, input().split()))
dp = 1
for a in A:
    dp |= dp << a

dp >>= k
if not dp & 1:
    print(-1)
    exit()


ans = 0
for a in A:
    if not dp >> a & 1:
        ans += 1
print(ans)