import bisect
import copy
import decimal
import fractions
import functools
import heapq
import itertools
import math
import random
import sys
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines

N,K=map(int,readline().split())
A=list(map(int,readline().split()))
mod=10**9+7
sum_A=sum(A)
dp=[0]*(100*N+1)
dp[N*K]=1
for a in A:
    a-=K
    prev=dp
    dp=[0]*(100*N+1)
    for i in range(100*N+1):
        if 0<=i+a<100*N+1:
            dp[i+a]+=prev[i]
    for i in range(100*N+1):
        dp[i]+=prev[i]
        dp[i]%=mod
ans=(sum(dp[N*K:])-1)%mod
print(ans)