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

#include <atcoder/modint>
using mint = atcoder::modint998244353;

set<int> cycle(vector<vector<int>> &G) {
	int N = G.size();
	set<int> ret;
	vector<int> path;
	vector<bool> vis_in(N), vis_out(N);
	auto dfs = [&](auto dfs, int cur, int pre) -> void {
		path.push_back(cur);
		vis_in[cur] = true;
		for( int &nxt : G[cur] ) {
			if( nxt == pre ) continue;
			if( !vis_in[nxt] ) {
				dfs(dfs, nxt, cur);
			}else if( !vis_out[nxt] ) {
				int s = find(path.begin(), path.end(), nxt)-path.begin();
				for( int i = s; i < path.size(); i++ ) ret.insert(path[i]);
			}
		}
		path.pop_back();
		vis_out[cur] = true;
	};
	dfs(dfs, 0, -1);
	return ret;
}

int main() {
	long long N, K;
	cin >> N >> K;
	vector<vector<int>> G(N);
	for( int i = 0; i < N; i++ ) {
		int u, v;
		cin >> u >> v;
		u--, v--;
		G[u].push_back(v);
		G[v].push_back(u);
	}
	set<int> S = cycle(G);
	vector<mint> dp(S.size()+1);
	for( int i = 2; i <= S.size(); i++ ) {
		dp[i] = K*mint(K-1).pow(i-1)-dp[i-1];
	}
	// for( int v : S ) cout << v+1 << endl;
	cout << (dp[S.size()]*mint(K-1).pow(N-S.size())).val() << endl;
}