#include<iostream>
#include<vector>
#include<utility>
using namespace std;
#include<atcoder/modint>
using mint = atcoder::modint998244353;
int main(){
	int N,K;cin>>N>>K;
	vector<int> A(N);
	mint sum = 1;
	mint c = 1;
	mint d = 1;
	for(int i=0;i<N;++i){
		cin>>A[i];
		sum *= A[i];
		c *= min(K-1,A[i]);
		d *= min(K,A[i]);
	}
	d -= c;
	mint div = sum - d - c;
	mint ans = div / sum;
	cout << ans.val() << endl;
	
}