N, K = map(int,input().split())
A = list(map(int,input().split()))
mod = int(1e9 + 7)

for i in range(N):
	A[i] -= K

dp = [[0 for j in range(20010)] for i in range(105)]
dp[0][10000] = 1
ans = 0

for i in range(N):
	for j in range(20005):
		dp[i+1][j] += dp[i][j]
		if j >= A[i] and j - A[i] < 20005:
			dp[i+1][j] += dp[i][j - A[i]]
		dp[i+1][j] %= mod

for j in range(10005):
	ans += dp[N][j + 10000]
	ans %= mod

ans -= 1
if ans < 0:
	ans += mod
print(ans)