#nullable enable

using System.Numerics;

const int Mod = 998244353;

static long Inverse(long v)
{
    var (res, k) = (1L, v);
    var p = Mod - 2;
    while (p > 0)
    {
        if ((p & 1) > 0) res = res * k % Mod;
        k = k * k % Mod;
        p >>= 1;
    }
    return res;
}

var inputs = Console.ReadLine()!.Split(' ');
var n = int.Parse(inputs[0]);
var k = int.Parse(inputs[1]);
var az = Console.ReadLine()!.Split(' ').Select(e => int.Parse(e)).ToArray();

var ans = 1L;
var ons = 1L;
for (var i = 0; i < n; i++)
{
    var a = az[i];
    var u = Math.Min(k, a);
    ans = ans * u % Mod * Inverse(a) % Mod;
    u = Math.Min(k - 1, a);
    ons = ons * u % Mod * Inverse(a) % Mod;
}
ans = (ans - ons + Mod) % Mod;
Console.WriteLine(ans);