class Inv:
  def __init__(s, mod):
    s.MOD = mod
  def modpow(s, a, n):
    res = 1
    while n > 0:
      if n & 1:
        res = res * a % s.MOD
      a = a * a % s.MOD
      n >>= 1
    return res
  def invx(s, a):
    return s.modpow(a, s.MOD - 2)
  def invpowL(s, a, n): # a^-x (0 <= x <= n)リスト
    ia = s.invx(a)
    L = [1] * (n + 1)
    for i in range(1, n + 1):
      L[i] = L[i - 1] * ia % s.MOD
    return L
  def invL(s, n): # 0 <= x <= n 逆元リスト
    I = [0, 1]
    for i in range(2, n + 1):
      I.append(s.MOD - I[s.MOD % i] * (s.MOD // i) % s.MOD)
    return I

N, K = list(map(int, input().split()))
A = list(map(int, input().split()))

MOD = 998244353

inv = Inv(MOD)
k = 1
kk = 1
for a in A:
  n = inv.invx(a)
  k *= min(a, K) * n % MOD
  kk *= min(a, (K - 1)) * n % MOD
  k %= MOD
  kk %= MOD

ans = k - kk
print(ans % MOD)