N,K=map(int, input().split())
D=[[] for i in range(N)]
E=[0]*N
for i in range(N):
  u,v=map(int, input().split())
  u-=1;v-=1
  D[u].append(v);D[v].append(u)
  E[u]+=1;E[v]+=1

from collections import deque
d=deque();V=[-1]*N
for i in range(N):
  if E[i]==1:
    d.append(i)
    V[i]=1

while d:
  now=d.popleft()
  E[now]-=1
  for nex in D[now]:
    if V[nex]==-1:
      E[nex]-=1
      if E[nex]==1:
        V[nex]=0
        d.append(nex)

mod=998244353
e=sum(E)//2
dp1=[1];dp2=[0]
for i in range(e-1):
  p,q=dp1[-1],dp2[-1]
  dp1.append(q)
  c=p*(K-1)+q*(K-2)
  dp2.append(c%mod)
ans=dp2[-1]*K
ans%=mod 
ans*=pow(K-1,N-e,mod)
ans%=mod
print(ans)