n, k = map(int, input().split())
A = list(map(int, input().split()))

DPl = [[0 for _ in range(k + 1)] for _ in range(n + 1)]
DPr = [[0 for _ in range(k + 1)] for _ in range(n + 1)]
DPl[0][0] = 1
DPr[n][0] = 1
for i in range(n):
    a = A[i]
    for j in range(k + 1):
        if DPl[i][j] > 0:
            DPl[i + 1][j] |= DPl[i][j]
            if j + a <= k:
                DPl[i + 1][j + a] |= DPl[i][j]
for i in range(n - 1, -1, -1):
    a = A[i]
    for j in range(k + 1):
        if DPr[i + 1][j] > 0:
            DPr[i][j] |= DPr[i + 1][j]
            if j + a <= k:
                DPr[i][j + a] |= DPr[i + 1][j]
ans = 0
if DPl[n][k]:
    for i in range(n):
        flag = True
        for j in range(k + 1):
            if DPl[i][j] and DPr[i + 1][k - j]:
                flag = False
                break
        if flag:
            ans += 1
else:
    ans = -1
print(ans)