local mod = 1000000007
local mfl = math.floor

local function bmul(x, y)
  local x1, y1 = mfl(x / 31623), mfl(y / 31623)
  local x0, y0 = x - x1 * 31623, y - y1 * 31623
  return (x1 * y1 * 14122 + (x1 * y0 + x0 * y1) * 31623 + x0 * y0) % mod
end

local function badd(x, y)
  return (x + y) % mod
end

local n, k = io.read("*n", "*n")
local a = {}
for i = 1, n do
  a[i] = io.read("*n") - k
end
local dp1, dp2 = {}, {}
for i = -10000, 10000 do
  dp1[10001 + i] = 0
end
dp1[10001 + 0] = 1

for i = 1, n do
  local src = i % 2 == 1 and dp1 or dp2
  local dst = i % 2 == 1 and dp2 or dp1
  for j = -10000, 10000 do
    dst[10001 + j] = src[10001 + j]
  end
  for j = -10000, 10000 do
    local v = src[10001 + j]
    local d = j + a[i]
    if -10000 <= d and d <= 10000 then
      dst[10001 + d] = badd(dst[10001 + d], src[10001 + j])
    end
  end
end
local tbl = n % 2 == 1 and dp2 or dp1
local ret = 0
for i = 0, 10000 do
  ret = badd(ret, tbl[10001 + i])
end
print((ret + mod - 1) % mod)