from collections import deque


class UnionFind:

    def __init__(self, N):
        self.tree_size = N
        self.parent = [i for i in range(N)]
        self.rank = [1 for _ in range(N)]

    def root(self, a):
        now = a
        while now != self.parent[now]:
            now = self.parent[now]
        return now

    def same(self, a, b):
        return self.root(a) == self.root(b)

    def merge(self, a, b):
        rta = self.root(a)
        rtb = self.root(b)
        if rta != rtb:
            if self.rank[rta] == self.rank[rtb]:
                self.parent[rtb] = self.parent[rta]
                self.rank[rta] += 1
            elif self.rank[rta] > self.rank[rtb]:
                self.parent[rtb] = self.parent[rta]
            else:
                self.parent[rta] = self.parent[rtb]


mod = 998244353

N, K = map(int, input().split())
graph = [[] for _ in range(N)]
tree = UnionFind(N)
dist = [N + 2 for _ in range(N)]
cnt = 0
dq = deque()
for i in range(N):
    u, v = map(int, input().split())
    u -= 1
    v -= 1
    if tree.same(u, v):
        dist[u] = 0
        dq.append(u)
        while len(dq) > 0:
            p = dq.popleft()
            for x in graph[p]:
                if dist[x] < N:
                    continue
                dist[x] = dist[p] + 1
                dq.append(x)
        cnt = dist[v] + 1
        break
    else:
        graph[u].append(v)
        graph[v].append(u)
        tree.merge(u, v)


dp = [[0, 0] for _ in range(N)]
dp[0][0] = K

for i in range(1, N):
    dp[i][0] = dp[i - 1][1]
    dp[i][1] = (dp[i - 1][0] * (K - 1) + dp[i - 1][1] * (K - 2)) % mod

ans = dp[cnt - 1][1]
for i in range(N - cnt):
    ans = (ans * (K - 1)) % mod
print(ans)