from collections import deque
N,K = map(int,input().split())
ldp = [[False] * (K+1) for _ in range(N+2)]
ldp[0][0] = True
rdp = [[False] * (K+1) for _ in range(N+2)]
rdp[N+1][0] = True
INF = float('inf')
MIN = [INF for _ in range(K+1)]
MAX = [0 for _ in range(K+1)]

A = [0] + list(map(int,input().split()))
for i in range(1,N+1):
    for k in range(K+1):
        ldp[i][k] |= ldp[i-1][k]
        if k >= A[i]:
            ldp[i][k] |= ldp[i-1][k-A[i]]
for i in reversed(range(1,N+1)):
    for k in range(K+1):
        rdp[i][k] |= rdp[i+1][k]
        if k >= A[i]:
            rdp[i][k] |= rdp[i+1][k-A[i]]
if ldp[N][K]:
    cnt = 0
    for i in range(1,N+1):
        flag = True
        for x in range(K+1):
            if ldp[i-1][x] and rdp[i+1][K-x]:
                flag = False
        cnt += flag
    print(cnt)
else:
    print(-1)