N,K=map(int,input().split())
A=list(map(int,input().split()))
DP=[[0]*(N*100+1) for i in range(N+1)]
DP[0][0]=1
mod=10**9+7
for i in range(N):
  for j in range((N-1)*100+1):
    DP[i+1][j+K]=(DP[i+1][j+K]+DP[i][j])%mod
    DP[i+1][j+A[i]]=(DP[i+1][j+A[i]]+DP[i][j])%mod
print((sum(DP[N][K*N:])-1)%mod)