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

dp = [[0]*(K+1) for _ in range(N+1)]
dp[0][0] = 1
for i in range(1,N+1):
    a = A[i-1]
    for j in range(K+1):
        dp[i][j] |= dp[i-1][j]
        if j+a<=K:
            dp[i][j+a] |= dp[i-1][j]

if dp[-1][-1]==0:
    exit(print(-1))

dpr = [set() for _ in range(N+1)]
dpr[-1].add(K)
ans = 0
for i in range(N,0,-1):
    a = A[i-1]
    c1, c2 = 0, 0
    for num in dpr[i]:
        if dp[i-1][num]>0:
            c1 += 1
            dpr[i-1].add(num)
        if num-a>=0 and dp[i-1][num-a]>0:
            c2 += 1
            dpr[i-1].add(num-a)
    l = len(dpr[i])
    if (c1==l and c2==0) or (c1==0 and c2==l):
        ans += 1
print(ans)