N,K = map(int,input().split())
lsA = list(map(int,input().split()))
dp = [0]*(30000+1)
offset = 15000
dp[offset] = 1
mod = 10**9+7
for i in range(N):
    a = lsA[i]-K
    dp2 = [0]*(30000+1)
    for j in range(30000+1):
        if 0<= j+a <=30000:
            dp2[j+a] += dp[j]
            dp2[j+a] %= mod
        dp2[j] += dp[j]
        dp2[j] %= mod
    dp = dp2
print((sum(dp[offset:])-1)%mod)