#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001LL


int main(){
	
	int n,m;
	cin>>n>>m;
	vector<int> a(n);
	rep(i,n)cin>>a[i];
	a.insert(a.begin(),0);
	a.push_back(0);
	int ok = 0;
	rep(i,a.size()-1){
		if(a[i]==a[i+1])ok++;
	}
	n = a.size()-1;
	vector<mint> dp(n+1);
	dp[ok] = 1;
	mint i2 = mint(2).inv();
	rep(_,m){
		vector<mint> ndp(n+1,0);
		rep(j,n+1){
			ndp[j] += dp[j] * j * (n-j);
			if(j+2<=n){
				ndp[j+2] += dp[j] * (n-j) * (n-j-1) * i2;
			}
			if(j-2>=0){
				ndp[j-2] += dp[j] * j * (j-1) * i2;
			}
		}
		swap(dp,ndp);
	}
	cout<<dp[n].val()<<endl;
	return 0;
}