n,k=map(int,input().split())
dp=[[False]*(k+1) for i in range(n+1)]
a=list(map(int,input().split()));dp[0][0]=True
for i in range(n):
    for j in range(k+1):
        if not dp[i][j]:
            continue
        dp[i+1][j]=True
        if j+a[i]<=k:
            dp[i+1][j+a[i]]=True
ans=0;c=dp[n][k]
if not c:
	print(-1);exit()
for i in range(k):
    dp[n][i]=False
for i in range(n-1,-1,-1):
    s=True
    for j in range(k+1):
        if dp[i][j] and dp[i+1][j]:
            s=False
        if dp[i][j]:
            if j+a[i]<=k and dp[i+1][j+a[i]] or dp[i+1][j]:
                dp[i][j]=True
            else:
                dp[i][j]=False
    if s:
        ans+=1
print(ans)