def main():
	import sys
	input = sys.stdin.readline
	n, k = map(int, input().split())
	a = list(map(int, input().split()))
	dp = [[0] * (k + 1) for _ in range(n + 1)]
	dp[0][0] = 1
	for i in range(n):
		for j in range(k + 1):
			if j - a[i] >= 0: dp[i + 1][j] |= dp[i][j - a[i]]
			dp[i + 1][j] |= dp[i][j]
	if not dp[n][k]: exit(print(-1))
	now = (n, k)
	l1 = []
	while now != (0, 0):
		cn, ck = now
		if 0 <= cn - 1 <= n and 0 <= ck - a[cn - 1] <= k and dp[cn - 1][ck - a[cn - 1]]:
			l1.append(cn - 1)
			now = (cn - 1, ck - a[cn - 1])
		else:
			now = (cn - 1, ck)
	l2 = []
	now = (n, k)
	while now != (0, 0):
		cn, ck = now
		if 0 <= cn - 1 <= n and dp[cn - 1][ck]:
			now = (cn - 1, ck)
		else:
			l2.append(cn - 1)
			now = (cn - 1, ck - a[cn - 1])
	print(len(set(l1) & set(l2)))
if __name__ == '__main__':
	main()