def f(A):
    DP=[[0]*(K+1) for _ in range(N+2)]
    DP[0][0]=1

    for i,a in enumerate(A,1):
        D=DP[i-1].copy()
        for y in range(K,a-1,-1):
            D[y]|=D[y-a]
        DP[i]=D
    DP[-1][0]=1
    return DP

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

assert (N<=10**4) and (K<=10**3)

X=f(A)
Y=f(A[::-1])[::-1]

if X[N][K]==0:
    Ans=-1
else:
    Ans=0
    for i in range(1,N+1):
        flag=1
        for x in range(K+1):
            flag&=~(X[i-1][x]&Y[i+1][K-x])
        Ans+=flag

print(Ans)