#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    int n, k;
    cin >> n >> k;
    vector<vector<int>> g(n);
    dsu uf(n);
    int s, t;
    rep(i,n){
        int a, b;
        cin >> a >> b;
        --a;--b;
        if(uf.same(a,b)){
            s = a;
            t = b;
            continue;
        }
        uf.merge(a,b);
        g[a].push_back(b);
        g[b].push_back(a);
    }
    queue<int> q;
    q.push(s);
    vector<int> dist(n, 1e9);
    dist[s] = 0;
    while(!q.empty()){
        int u = q.front();
        q.pop();
        for(int v : g[u]){
            if(dist[v]!=1e9) continue;
            q.push(v);
            dist[v] = dist[u] + 1;
        }
    }
    dbg(s,t);
    dbg(dist);
    vector<vector<mint>> dp(dist[t]+1, vector<mint>(2));
    dp[0][0] = 1;
    rep(i,dist[t]){
        dp[i+1][0] += dp[i][1];
        dp[i+1][1] += dp[i][0] * (k-1) + dp[i][1] * (k-2); 
    }
    mint ans = dp[dist[t]][1];
    ans *= k;
    ans *= mint(k-1).pow(n-dist[t]-1);
    cout << ans.val() << endl;
    return 0;
}