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


#include<atcoder/modint>
using mint = atcoder::modint998244353;
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n,k;
    cin>>n>>k;
    vector<mint> dp(n+1,0);
    dp[1] = 1;
    dp[2] = mint(k) * mint(k-1);
    for(int i = 3;i<=n;i++){
        dp[i] = mint(k-2) * dp[i-1];
        if(i>3) dp[i] += mint(k-1) * dp[i-2];
    }
    mint ans = 0;
    vector<vector<int>> g(n);
    vector<int> cnt(n,0);
    int all = 0;
    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);
        cnt[u]++;
        cnt[v]++;
    }
    vector<int> que;
    for(int i = 0;i<n;i++) if(cnt[i]==1) que.push_back(i);
    for(int i = 0;i<que.size();i++){
        int ni = que[i];
        for(auto&to:g[ni]){
            cnt[to]--;
            if(cnt[to]==1) que.push_back(to);
        }
    }
    int use = n - que.size();
    ans = dp[use] * mint(k-1).pow(que.size());
    cout<<ans.val()<<endl;
}