#include <bits/stdc++.h>
//#define int long long
#pragma GCC optimize(2)
#define endl "\n"
using namespace std;

using ll = long long;
const int MOD = 998244353;
const int N = 1e6 + 5;

ll quickPower(ll a, ll n) {
    if (a == 0)
        return 0;
    ll res = 1;
    while (n) {
        if (n & 1)
            res = res * a % MOD;
        a = a * a % MOD;
        n >>= 1;
    }
    return res;
}

ll inv(ll x) {
    return quickPower(x, MOD - 2);
}

set<int> edges[N];
pair<int, int> query[N];
int dep[N];

void dfs(int u, int fa) {
    dep[u] = dep[fa] + 1;
    for (int v : edges[u]) {
        if (v == fa)
            continue;
        dfs(v, u);
    }
}

struct DSU {
    int fa[N];
    int cnt[N];
    int dep[N];
    DSU(int n = N - 1) {
        for (int i = 1; i <= n; i++) {
            fa[i] = i;
            cnt[i] = 1;
        }
    }

    void init(int n, int* dep) {
        for (int i = 1; i <= n; i++) {
            this->dep[i] = dep[i];
        }
    }

    int find(int x) {
        return fa[x] = x == fa[x] ? x : find(fa[x]);
    }

    void merge(int u, int v) {
        u = find(u), v = find(v);
        if (dep[u] > dep[v]) {
            fa[u] = v;
            cnt[v] += cnt[u];
        }
        else {
            fa[v] = u;
            cnt[u] += cnt[v];
        }
    }
} dsu;

int main() {
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);

    int n;
    cin >> n;
    for (int i = 1; i <= n - 1; i++) {
        cin >> query[i].first >> query[i].second;
    }
    for (int i = 1; i <= n - 1; i++) {
        int u, v;
        cin >> u >> v;
        edges[u].emplace(v);
        edges[v].emplace(u);
    }

    dfs(1, 0);
    dsu.init(n, dep);

    ll ans = 1;
    for (int i = 1; i <= n - 1; i++) {
        auto [u, v] = query[i];
        u = dsu.find(u), v = dsu.find(v);
        if (!edges[u].count(v))
            ans = 0;
        ans = ans * dsu.cnt[u] % MOD * dsu.cnt[v] % MOD;
        dsu.merge(u, v);
    }
    cout << inv(ans) << endl;

    return 0;
}