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

dp1 = [[False] * (K + 1) for _ in range(N + 1)]
dp2 = [[False] * (K + 1) for _ in range(N + 1)]

for i in range(N + 1):
    dp1[i][0] = True
    dp2[i][0] = True

for i in range(N):
    a = A[i]
    for j in range(K + 1):
        dp1[i + 1][j] = dp1[i][j]
    for j in range(K + 1 - a):
        dp1[i + 1][j + a] |= dp1[i][j]
for i in range(N - 1, -1, -1):
    a = A[i]
    for j in range(K + 1):
        dp2[i][j] = dp2[i + 1][j]
    for j in range(K + 1 - a):
        dp2[i][j + a] |= dp2[i + 1][j]

if not dp1[-1][K]:
    print(-1)
    exit()

ans = 0
for i, a in enumerate(A):
    for j in range(K + 1):
        k = K - j
        if dp1[i][j] & dp2[i + 1][k]:
            break
    else:
        ans += 1
print(ans)