#include <bits/stdc++.h>
#include <atcoder/all>
#include <boost/polygon/point_data.hpp>
#include <boost/polygon/voronoi.hpp>
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define all(x) begin(x),end(x)
#define sz(x) (int)(x).size()
using namespace std;
using namespace atcoder;
using ll=long long;
using ld=long double;
using vll=vector<ll>;
using vvll=vector<vll>;
using vi=vector<int>;
using vvi=vector<vi>;
using pll=pair<ll,ll>;

using mint=modint998244353;

// using BoostPoint=boost::polygon::point_data<int>;
// using Voronoi=boost::polygon::voronoi_diagram<double>;


int main()
{
  	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	/**
	 * まず、Pr[M=K] = Pr[K>=M] - Pr[K-1>=M]
	 * S = {i:A_i>=K}, t = |S| の時
	 * Pr[K>=M] = \Prod_{i\in S} K/A_i 
	 * と　Pr[K-1>=M] = \Prod_{i\in S} (K-1)/A_i が成り立つ
	 */
	int N,K;
	cin>>N>>K;
	mint p=1;
	int t=0;
	rep(i,0,N){
		int a;
		cin>>a;
		if(a<K)continue;//関係ないやつです
		t++;
		mint b=a;
		p*=b;
	}
	mint x=K,y=K-1;
	cout<<((x.pow(t)-y.pow(t))*p.inv()).val()<<'\n';

}