#ifdef DEBUG
#define _GLIBCXX_DEBUG
#else
#pragma GCC target("avx2")
#pragma GCC optimize("Ofast,unroll-loops")
#endif
#include <bits/stdc++.h>
#include <atcoder/all>
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define ALL(a) a.begin(), a.end()
#undef long
#define long long long
using namespace std;
using mint = atcoder::modint998244353;
ostream& operator<<(ostream& os, const mint& a) {
	return os << a.val();
}
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& a) {
	const int n = a.size();
	rep(i, n) os << a[i] << " \n"[i + 1 == n];
	return os;
}
template<typename T>
istream& operator>>(istream& os, const vector<T>& a) {
	for (T& i : a) os >> i;
	return os;
}
void chmin(int& x, int y) {
	if (x > y) x = y;
}
void chmax(int& x, int y) {
	if (x < y) x = y;
}
void solve() {
	constexpr int inf = 1e7;
	int n, col; cin >> n >> col;
	atcoder::dsu dsu(n);
	vector<vector<int>> g(n);
	int loop = 1;
	rep(ddd, n) {
		int u, v; cin >> u >> v; u--, v--;
		if (dsu.same(u, v)) {
			vector<int> uu(n, inf);
			queue<int> q;
			q.push(u);
			uu[u] = 0;
			while (!q.empty()) {
				const int x = q.front(); q.pop();
				for (int i : g[x]) {
					if (uu[i] != inf) continue;
					uu[i] = uu[x] + 1;
					q.push(i);
				}
			}
			for (int now = v; now != u;) {
				for (int i : g[now]) {
					if (uu[i] + 1 == uu[now]) {
						now = i;
						loop++;
						break;
					}
				}
			}
			break;
		}
		dsu.merge(u, v);
		g[u].push_back(v);
		g[v].push_back(u);
	}
	vector<mint> fact(n + 1), finv(n + 1);
	fact[0] = 1;
	for (int i = 1; i <= n; i++) fact[i] = i * fact[i - 1];
	finv[n] = fact[n].inv();
	for (int i = n; i >= 1; i--) finv[i - 1] = i * finv[i];
	mint ans = 0;
	for (int i = 0; i <= loop; i++) {
		const mint comb = finv[i] * finv[loop - i] * fact[loop];
		const mint mul1 = mint(-1).pow(i);
		const mint mul2 = mint(col).pow(max(1, loop - i));
		ans += comb * mul1 * mul2;
	}
	ans *= mint(col - 1).pow(n - loop);
	cout << ans << '\n';
}
int main() {
	// srand((unsigned)time(NULL));
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cout << fixed << setprecision(40);
	solve();
	return 0;
}