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

x = 1
y = 1
deno = 1
for a in A:
    if a < K: continue

    x *= K
    x %= MOD

    y *= K-1
    y %= MOD

    deno *= pow(a, MOD-2, MOD)
    deno %= MOD

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