from collections import defaultdict

N,K=map(int,input().split())
M=100*N
A=list(map(lambda x:int(x)-K,input().split()))

Mod=10**9+7
D=defaultdict(int)
D[0]=1

for i in range(1,N+1):
    E=D
    D=defaultdict(int)

    a=A[i-1]

    for k in range(-M,M+1):
        D[k]=E[k]+E[k-a]
        D[k]%=Mod

X=0
for k in D:
    if k>=0: X+=D[k]

print((X-1)%Mod)