/**
	author:  shobonvip
	created: 2025.04.20 16:35:17
**/

#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)
#define all(v) v.begin(), v.end()

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

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

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int n, m; cin >> n >> m;
	vector<int> a(n);
	rep(i,0,n) {
		cin >> a[i];
	}

	vector<mint> dp;
	vector<int> val = {1, m + 1};
	val.push_back(a[0]+1);
	val.push_back(a[1]+1);
	sort(all(val));
	val.erase(unique(all(val)),val.end());

	dp.resize((int)val.size() - 1);
	rep(x,0,(int)val.size()-1) {
		dp[x] = val[x+1] - val[x];
	}

	rep(i,1,n){
		vector<int> nxtval = {1, m+1};
		nxtval.push_back(a[i]+1);
		if (i+1 < n) {
			nxtval.push_back(a[i+1]+1);
		}
		if (i-1 >= 0) {
			nxtval.push_back(a[i-1]+1);
		}
		sort(all(nxtval));
		nxtval.erase(unique(all(nxtval)),nxtval.end());

		vector<mint> nxtdp;
		nxtdp.resize((int)nxtval.size()-1);

		rep(x,0,(int)val.size() - 1){
			rep(y,0,(int)nxtval.size() - 1){
				int cnt0 = 0;
				int cnt1 = 0;
				if (val[x] > a[i-1]) cnt0++;
				if (nxtval[y] > a[i]) cnt0++;
				if (nxtval[y] > a[i-1]) cnt1++;
				if (val[x] > a[i]) cnt1++;
				if(cnt0 < cnt1) {
					continue;
				}
				nxtdp[y] += dp[x] * (nxtval[y+1]-nxtval[y]);
			}
		}

		swap(val,nxtval);
		swap(dp,nxtdp);

	}

	mint ans = mint(m).pow(n) - sum(dp);

	//cout << sum(dp).val()<< endl;

	mint keis = mint(m).pow(n-1);
	for (int i=0; i<n; i++) {
		ans += keis * max(0, m-a[i]);
	}

	cout << ans.val() << endl;

}