#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  VVI to(n);
  rep(_, n) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    to[u].emplace_back(v);
    to[v].emplace_back(u);
  }
  VI st;
  VI in_stack(n);
  auto dfs = [&](auto&& self, int u, int p) -> bool {
    if (in_stack[u]) {
      st.erase(st.begin(), find(all(st), u));
      return true;
    }
    st.emplace_back(u);
    in_stack[u] = true;
    for (int v : to[u]) if (v != p) {
      if (self(self, v, u)) return true;
    }
    in_stack[u] = false;
    st.pop_back();
    return false;
  };
  auto res = dfs(dfs, 0, -1);
  assert(res);
  int len = st.size();
  mint dp[2];
  dp[0] = k;
  rep(_, len - 1) {
    mint ndp[2];
    ndp[1] += dp[0] * (k - 1);
    ndp[0] += dp[1];
    ndp[1] += dp[1] * (k - 2);
    swap(dp, ndp);
  }
  mint ans = dp[1] * mint(k - 1).pow(n - len);
  cout << ans.val() << '\n';
}