/* -*- coding: utf-8 -*-
 *
 * 2531.cc:  No.2531 Coloring Vertices on Namori - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 200000;
const int MOD = 998244353;

/* typedef */

using ll = long long;
using vi = vector<int>;

/* global variables */

vi nbrs[MAX_N];
int ps[MAX_N], cis[MAX_N], ds[MAX_N];
int dp0[MAX_N], dp1[MAX_N];

/* subroutines */

int powmod(int a, int b) {
  int p = 1;
  while (b > 0) {
    if (b & 1) p = (ll)p * a % MOD;
    a = (ll)a * a % MOD;
    b >>= 1;
  }
  return p;
}

/* main */

int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  for (int i = 0; i < n; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    u--, v--;
    nbrs[u].push_back(v);
    nbrs[v].push_back(u);
  }

  int l = 0;
  fill(ds, ds + n, -1);
  ps[0] = -1, ds[0] = 0;
  for (int u = 0; l <= 0 && u >= 0;) {
    auto &nbru = nbrs[u];
    int up = ps[u];

    if (cis[u] < nbru.size()) {
      int v = nbru[cis[u]++];
      if (v != up) {
	if (ds[v] < 0) {
	  ps[v] = u, ds[v] = ds[u] + 1;
	  u = v;
	}
	else {
	  l = ds[u] - ds[v] + 1;
	  break;
	}
      }
    }
    else
      u = up;
  }
  //printf(" l=%d\n", l);

  dp0[0] = k, dp1[0] = 0;
  for (int i = 1; i < l; i++) {
    dp0[i] = dp1[i - 1];
    dp1[i] =
      ((ll)dp0[i - 1] * (k - 1) % MOD +
       (ll)dp1[i - 1] * (k - 2) % MOD) % MOD;
  }

  int x = (ll)dp1[l - 1] * powmod(k - 1, n - l) % MOD;
  printf("%d\n", x);
  
  return 0;
}