n, k = map(int,input().split())
dp = [[0 for i in range(k + 1)] for j in range(n + 1)]
dp[0][0] = 1
a = list(map(int,input().split()))

for i in range(n):
	for j in range(k+1):
		dp[i+1][j] |= dp[i][j]
		if j + a[i] <= k:
			dp[i+1][j + a[i]] |= dp[i][j]

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

fukugendp = [[0 for i in range(k + 1)] for j in range(n+1)]
fukugendp[n][k] = 1

t = 0

for i in range(n-1, -1, -1):
	mode = 1
	for j in range(k, -1, -1):
		if fukugendp[i+1][j] == 1:
			if dp[i][j] == 1:
				fukugendp[i][j] = 1
			if j-a[i] >= 0:
				if dp[i][j - a[i]] == 1:
					fukugendp[i][j - a[i]] = 1
			if fukugendp[i][j] == 1:
				mode = 0
	if mode:
		t += 1
			
#for i in range(n+1):
#	print(fukugendp[i])

print(t)