"""

https://yukicoder.me/problems/no/2531



"""

import math
import sys
from sys import stdin

def modfac(n, MOD):
 
    f = 1
    factorials = [1]
    for m in range(1, n + 1):
        f *= m
        f %= MOD
        factorials.append(f)
    inv = pow(f, MOD - 2, MOD)
    invs = [1] * (n + 1)
    invs[n] = inv
    for m in range(n, 1, -1):
        inv *= m
        inv %= MOD
        invs[m - 1] = inv
    return factorials, invs


def modnCr(n,r): #上で求めたfacとinvsを引数に入れるべし(上の関数で与えたnが計算できる最大のnになる)
    return fac[n] * inv[n-r] * inv[r] % mod

def cycle(r,K):

    ret = 0
    pp = 1
    for i in range(r-1):
        ret += pp * K * pow(K-1,r-1-i,mod)
        pp *= -1

    return ret % mod

mod = 998244353
fac,inv = modfac(10**6+100,mod)

N,K = map(int,stdin.readline().split())

lis = [ [] for i in range(N) ]
inlis = [0] * N

#print (cycle(N,K))

for i in range(N):

    u,v = map(int,stdin.readline().split())

    u -= 1
    v -= 1
    lis[u].append(v)
    lis[v].append(u)
    inlis[u] += 1
    inlis[v] += 1

from collections import deque
q = deque()

for i in range(N):
    if inlis[i] <= 1:
        q.append(i)

tree = 0
while q:
    v = q.popleft()
    tree += 1
    for nex in lis[v]:
        inlis[nex] -= 1
        if inlis[nex] == 1:
            q.append(nex)
            inlis[nex] = -1

print (cycle(N-tree,K) * pow(K-1,tree,mod) % mod)