#include <atcoder/all>
#include <cassert>
#include <iostream>
#include <queue>
#include <set>
#include <vector>
using namespace std;
using namespace atcoder;
using ll = long long;

ll mod = 998244353;


int main() {
    ll N, K;
    cin >> N >> K;
    vector<ll> u(N);
    vector<ll> v(N);
    for (ll i = 0; i < N; i++) {
        cin >> u[i] >> v[i];
        u[i]--;
        v[i]--;
    }
    vector<ll> dist(N, N + 2);
    queue<ll> que;
    vector<vector<ll>> graph(N, vector<ll>(0));
    dsu tree(N);
    ll cnt = 0;
    for (ll i = 0; i < N; i++) {
        if (!tree.same(u[i], v[i])) {
            graph[u[i]].push_back(v[i]);
            graph[v[i]].push_back(u[i]);
            tree.merge(u[i], v[i]);
        } else {
            que.push(u[i]);
            dist[u[i]] = 0;
            while (que.size()) {
                ll p = que.front();
                que.pop();
                for (ll x : graph[p]) {
                    if (dist[x] < N) {
                        continue;
                    }
                    dist[x] = dist[p] + 1;
                    que.push(x);
                }
            }
            cnt = dist[v[i]] + 1;
            break;
        }
    }
    vector<vector<ll>> dp(N, vector<ll>(2, 0));
    dp[0][0] = K;
    for (ll i = 1; i < N; i++) {
        dp[i][0] = dp[i - 1][1];
        dp[i][1] = (dp[i - 1][0] * (K - 1) + dp[i - 1][1] * (K - 2)) % mod;
    }
    ll ans = dp[cnt - 1][1];
    for (ll i = 0; i < N - cnt; i++) {
        ans = (ans * (K - 1)) % mod;
    }
    cout << ans << endl;
    for (int i = 0; i < N; i++) {
        assert(tree.same(0, i));
    }
    return 0;
}