from types import GeneratorType
from collections import deque

def bootstrap(f, stack=[]):
    def wrappedfunc(*args, **kwargs):
        if stack:
            return f(*args, **kwargs)
        to = f(*args, **kwargs)
        while True:
            if type(to) is GeneratorType:
                stack.append(to)
                to = next(to)
            else:
                stack.pop()
                if not stack:
                    break
                to = stack[-1].send(to)
        return to
    return wrappedfunc

N, K = map(int, input().split())
G = [[] for _ in range(N)]
for _ in range(N):
    u, v = map(int, input().split())
    G[u-1].append(v-1)
    G[v-1].append(u-1)

MOD = 998244353

@bootstrap
def dfs(n, pre):
    visited[n] = True
    stack.append(n)
    for v in G[n]:
        if not visited[v]:
            yield dfs(v, n)
        elif v != pre and not finished[v]:
            for s in stack:
                cycle.append(s)
            cycle.append(v)
    finished[n] = True
    stack.pop()
    yield

stack = []
cycle = []
visited = [False]*N
finished = [False]*N
dfs(0, -1)

c = cycle.pop()
cycle = cycle[::-1]
while cycle[-1] != c:
    cycle.pop()

dp = [[0]*2 for _ in range(len(cycle))]
dp[0][0] = 1
for i in range(len(cycle)-1):
    dp[i+1][1] += dp[i][0]*(K-1)
    dp[i+1][1] %= MOD
    dp[i+1][0] += dp[i][1]
    dp[i+1][0] %= MOD
    dp[i+1][1] += dp[i][1]*(K-2)
    dp[i+1][1] %= MOD
ans = dp[-1][1]*K%MOD

S = set(cycle)
visited = [False]*N
for c in cycle:
    visited[c] = True
for c in cycle:
    for v in G[c]:
        if v not in S:
            que = deque()
            que.append(v)
            visited[v] = True
            cnt = 1
            while que:
                n = que.popleft()
                for v in G[n]:
                    if not visited[v]:
                        visited[v] = True
                        que.append(v)
                        cnt += 1
            ans *= pow(K-1, cnt, MOD)
            ans %= MOD

print(ans)