#include <bits/stdc++.h>
using namespace std;
const long long MOD = 998244353;
int main(){
  int N, K;
  cin >> N >> K;
  vector<vector<int>> E(N);
  for (int i = 0; i < N; i++){
    int u, v;
    cin >> u >> v;
    u--;
    v--;
    E[u].push_back(v);
    E[v].push_back(u);
  }
  vector<int> deg(N);
  for (int i = 0; i < N; i++){
    deg[i] = E[i].size();
  }
  queue<int> Q;
  for (int i = 0; i < N; i++){
    if (deg[i] == 1){
      Q.push(i);
    }
  }
  long long ans = 1;
  int cnt = N;
  while (!Q.empty()){
    int v = Q.front();
    Q.pop();
    ans *= K - 1;
    ans %= MOD;
    cnt--;
    for (int w : E[v]){
      deg[w]--;
      if (deg[w] == 1){
        Q.push(w);
      }
    }
  }
  long long tmp = 1;
  for (int i = 0; i < cnt; i++){
    tmp *= K - 1;
    tmp %= MOD;
  }
  if (cnt % 2 == 0){
    tmp += K - 1;
  } else {
    tmp += MOD - (K - 1);
  }
  tmp %= MOD;
  ans *= tmp;
  ans %= MOD;
  cout << ans << endl;
}