#include <stdio.h>

typedef struct list {
  int v;
  struct list *n;
} list;

int func (int v, int prev, int tmp_d, list **e, int *d) {
  list *l = e[v];
  
  if (d[v] > 0) {
    return tmp_d-d[v];
  }
  
  d[v] = tmp_d;
  while (l != NULL) {
    if (l->v != prev) {
      int res = func(l->v, v, tmp_d+1, e, d);
      if (res > 0) {
        return res;
      }
    }
    l = l->n;
  }
  
  return 0;
}

int main () {
  int n = 0;
  int k = 0;
  int u = 0;
  int v = 0;
  
  int res = 0;
  
  long long ans = 0LL;
  long long mod_num = 998244353LL;
   
  list *e[200000] = {};
  
  list pool[400000] = {};
  int used = 0;
  
  int d[200000] = {};
  int len = 0;
  
  long long dp[200000][2] = {};
  
  res = scanf("%d", &n);
  res = scanf("%d", &k);
  for (int i = 0; i < n; i++) {
    res = scanf("%d", &u);
    res = scanf("%d", &v);
    u--;
    v--;
    pool[used].v = v;
    pool[used].n = e[u];
    e[u] = pool+used;
    used++;
    pool[used].v = u;
    pool[used].n = e[v];
    e[v] = pool+used;
    used++;
  }
  
  len = func(0, -1, 1, e, d);
  
  dp[0][0] = ((long long)k);
  dp[0][1] = 0LL;
  for (int i = 1; i < len; i++) {
    dp[i][0] = dp[i-1][1];
    dp[i][1] = dp[i-1][0]*((long long)(k-1))+dp[i-1][1]*((long long)(k-2));
    dp[i][1] %= mod_num;
  }
  
  ans = dp[len-1][1];
  for (int i = 0; i < n-len; i++) {
    ans *= ((long long)(k-1));
    ans %= mod_num;
  }
  
  printf("%lld\n", ans);
  return 0;
}