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

import sys
if N == 1:
    if A[0] == K:
        print(1)
    else:
        print(-1)
    exit()

dp = [[0] * (K + 1) for _ in range(N)]
if A[0] <= K:
    dp[0][A[0]] = 1
dp[0][0] = 1
for i in range(N-1):
    for j in range(K+1):
        if dp[i][j]:
            dp[i+1][j] = 1
            if j + A[i+1] <= K:
                dp[i+1][j+A[i+1]] = 1
rdp = [[0] * (K + 1) for _ in range(N)]
if A[-1] <= K:
    rdp[-1][A[-1]] = 1
rdp[-1][0] = 1
for i in range(N-1,0,-1):
    for j in range(K+1):
        if rdp[i][j]:
            rdp[i-1][j] = 1
            if j + A[i-1] <= K:
                rdp[i-1][j+A[i-1]] = 1
if dp[-1][K] == 0:
    print(-1)
    exit()
ans = 0
for i in range(N):
    if i == 0:
        if rdp[1][K] == 0:
            ans += 1
        continue
    if i == N-1:
        if dp[N-2][K] == 0:
            ans += 1
        continue
    t = K - A[i]
    flag = True
    for j in range(K+1):
        if dp[i-1][j] == 1 and rdp[i+1][K-j] == 1:
            flag = False
            break
    if flag:ans += 1
print(ans)