#include <bits/stdc++.h>
#define int long long
using namespace std;
const int maxn = 1e6 + 5;
const int mod = 998244353;

int n, ans = 1;
int a[maxn], b[maxn], id[maxn], fa[maxn], cnt[maxn], depth[maxn];

vector<int> G[maxn];

int root(int x) { return id[x] == x ? x : id[x] = root(id[x]); }

void unite(int x, int y)
{
	x = root(x); y = root(y);
	if (x == y) return;
	id[x] = y;
	cnt[y] += cnt[x];
	depth[y] = min(depth[x], depth[y]);
}

void dfs(int u, int f, int d)
{
	fa[u] = f; depth[u] = d;
	for (int i = 0; i < G[u].size(); i++)
		if (G[u][i] != f)
			dfs(G[u][i], u, d + 1);
}

int qpow(int x, int p)
{
	int t = 1;
	while (p)
	{
		if (p & 1) (t *= x) %= mod;
		(x *= x) %= mod;
		p >>= 1;
	}
	return t;
}

signed main()
{
	cin >> n;
	for (int i = 1; i <= n; i++)
		id[i] = i, cnt[i] = 1;
	for (int i = 1; i < n; i++)
		cin >> a[i] >> b[i];
	for (int i = 1; i < n; i++)
	{
		int u, v;
		cin >> u >> v;
		G[u].push_back(v);
		G[v].push_back(u);
	}
	dfs(1, 0, 1);
	for (int i = 1; i < n; i++)
	{
		int A = root(a[i]), B = root(b[i]);
		(ans *= cnt[A] * cnt[B]) %= mod;
		int u = depth[A] > depth[B] ? A : B, v = A + B - u;
		bool check = false;
		for (int j = 0; j < G[u].size(); j++)
			if (root(G[u][j]) == v)
				check = true;
		if (!check)
		{
			cout << 0;
			return 0;
		}
		unite(A, B);
	}
	cout << qpow(ans, mod - 2);
	return 0;
}