MOD = 998244353
N, K = map(int, input().split())
A = list(map(int, input().split()))

deno = 1
for a in A:
    deno *= pow(a, MOD-2, MOD)
    deno %= MOD

x = 1
y = 1
for a in A:
    x *= min(a, K)
    x %= MOD

    y *= min(a, K-1)
    y %= MOD

ans = ((x * deno) - (y * deno)) % MOD
print(ans)