#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll const m = 998244353;
int par[200020];
int siz[200020];
void init(int N) {
	iota(par, par + N, 0);
	fill(siz, siz + N, 1);
}
int root(int v) {
	return par[v] = (v == par[v] ? v : root(par[v]));
}
bool merge(int a, int b) {
	a = root(a); b = root(b);
	if (a == b) {
		return true;
	}
	if (siz[a] < siz[b]) swap(a, b);
	siz[a] += siz[b];
	par[b] = a;
	return false;
}
int main () {
	int N; ll K;
	cin >> N >> K;
	int len = 0;
	init(N);
	std::vector<vector<int>> gr(N);
	for (int i = 0; i < N; i ++) {
		int a, b;
		cin >> a >> b;
		if (merge(--a, --b)) {
			vector<int> D(N, -1);
			D[a] = 0;
			queue<int> que;
			que.push(a);
			while (!que.empty()) {
				int u = que.front();
				que.pop();
				for (auto v : gr[u]) {
					if (D[v] == -1) {
						D[v] = D[u] + 1;
						que.push(v);
					}
				}
			}
			len = D[b] + 1;
		}
		gr[a].push_back(b);
		gr[b].push_back(a);
	}
	ll ans = K;
	ll hog = K;
	if (len > 1) {
		ans = (K * (K - 1)) % m;
		hog = (K * (K - 1)) % m;
	}
	for (int i = 2; i < len; i ++) {
		ans = (K - 2) * ans + (K - 1) * ((hog - ans + m) % m);
		ans %= m;
		hog = (hog * (K - 1)) % m;
	}
	for (int i = 0; i < N - len; i ++) {
		ans = (ans * (K - 1)) % m;
	}
	cout << ans << endl;
}