#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll const m = 998244353;
int main () {
	int N; ll K;
	cin >> N >> K;
	std::vector<vector<int>> gr(N);
	for (int i = 0; i < N; i ++) {
		int a, b;
		cin >> a >> b;
		if (a > b) swap(a, b);
		gr[--a].push_back(--b);
	}
	vector<int> D(N, -1), D2(N, -1);
	int len = 0;
	for (int i = 0; i < N; i ++) {
		if (D[i] != -1) continue;
		D[i] = D2[i] = 0;
		vector<int> V;
		queue<int> que;
		que.push(i);
		V.push_back(i);
		while (!que.empty()) {
			int u = que.front();
			for (int v : gr[u]) {
				if (u == v) {
					len = 1;
					break;
				}
				if (D2[v] == -1) {
					D[v] = D2[v] = D2[u] + 1;
					que.push(v);
					V.push_back(v);
				} else {
					int p = D2[u] + 1, q = D2[v];
					len = p - q + 2;
					break;
				}
			}
		}
		if (len) break;
		for (auto u : V) {
			D2[u] = -1;
		}
	}
	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;
}