#ifndef INCLUDED_MAIN
#define INCLUDED_MAIN

#include __FILE__

int main(){
    ll n,k; cin>>n>>k;
    vl a(n);
    rep(i,n) cin>>a[i];
    ll all_prod=1;
    rep(i,n) {
        all_prod*=a[i];
        all_prod%=mod;
    }
    ll pdinv=modinv(all_prod,mod);
    auto funk=[&](ll f) {
        ll res=1;
        rep(i,n) {
            res*=(min(f,a[i]));
            res%=mod;
        }
        res*=pdinv;
        res%=mod;
        return res;
    };

    ll ans=funk(k)-funk(k-1);
    if(ans<0) ans+=mod;
    cout<<ans<<nl;
}

/////// library zone ///////
#else
#include <bits/stdc++.h>
#include <atcoder/segtree>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define srep(i,l,r) for(ll i=l;i<=r;i++)
using ll = long long;
using ld = long double;
const ll mod=998244353;
#define vout(v) for(auto i :v) cout<<i<<" ";
#define INF 9223300000000000000ll
#define Winf 5e12
#define nl "\n"
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define vl vector<ll>
#define vc vector<char>


ll op(ll a,ll b) {return a+b;}
ll e() {return 0ll;}



template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}

void no() { cout<<"No"<<nl;}
void yes() { cout<<"Yes"<<nl;}
void yn(bool a) {
    cout<<(a ? "Yes":"No")<<nl;
}

ll sum(vector<ll>& a) {
    ll ans=0;
    for(auto i:a) ans+=i;
    return ans;
}



ll modpow(ll fl, ll po, ll mode) {  // mode: 0=modなし, 1=modあり
    ll ret=1;
    if (mode) {
        while (po>0) {
            if (po&1) ret=(ret*fl)%mod;
            fl=(fl*fl)%mod;
            po>>=1;
        }
    } else {
        while (po>0) {
            if(po&1) ret*=fl;
            fl*=fl;
            po>>=1;
        }
    }
    return ret;
}

ll modinv(ll a, ll mod) { //拡張Euclidによるmodでの逆元, a*u+mod*v=1を解く
	ll b=mod,u=1,v=0;
	while (b) {
		ll t=a/b;
		a-=t*b;
        swap(a,b);
		u-=t*v;
        swap(u,v);
	}
	u%=mod; 
	if (u < 0) u+=mod;
	return u;
}
#endif