N, K = map(int, input().split())
a = list(map(int,input().split()))
mod = 10**9+7
dp = [[0]*20001 for _ in range(N)]
dp[0][a[0]-K+10000] = 1
for i in range(1,N):
    for j in range(20001):
        dp[i][j] = dp[i-1][j]
    dp[i][a[i]-K+10000] += 1
    for j in range(20001):
        dp[i][j] %= mod
        if 0<=j+a[i]-K<=20000:
            dp[i][j+a[i]-K] += dp[i-1][j]
print(sum(dp[-1][10000:])%mod)