#include<bits/stdc++.h>
using ll = long long;
const int mod = 998244353;

inline ll qpow(ll a, ll b) {
    if (b == 0) return 1ll;
    if (b == 1) return a;
    ll res = qpow(a, b / 2);
    res = res * res % mod;
    if (b & 1) return res * a % mod;
    return res;
}

void solve() {
    int n;
    std::cin >> n;

    std::vector<int> fa(n), dep(n), siz(n), p(n);
    std::vector<std::vector<int>> adj(n);
    std::vector<std::pair<int, int>> a(n - 1);
    for (int i = 0; i < n - 1; i++) {
        std::cin >> a[i].first >> a[i].second;
        a[i].first --;
        a[i].second --;
    }

    for (int i = 1; i < n; i++) {
        int x, y;
        std::cin >> x >> y;
        x--; y--;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    auto dfs = [&](auto& self, int u, int fno) -> void {
        for (auto v : adj[u]) {
            if (v == fno) continue;
            p[v] = u;
            dep[v] = dep[u] + 1;
            self(self, v, u);
        }
    };

    dfs(dfs, 0, -1);
    for (int i = 0; i < n; i++) fa[i] = i, siz[i] = 1;
    
    auto find = [&](auto& self, int x) -> int {
        if (fa[x] == x) {
            return x;
        }
        int t = self(self, fa[x]);
        fa[x] = t;
        return t;
    };
    auto merge = [&](int x, int y) {
        x = find(find, x);
        y = find(find, y);
        if (dep[x] < dep[y]) std::swap(x, y);
        fa[x] = y;
        dep[x] = dep[y];
        siz[y] += siz[x];
    };

    ll ans = 1;
    for (int i = 0; i < n - 1; i++) {
        int x = a[i].first, y = a[i].second;
        int fx = find(find, x), fy = find(find, y);
        if (dep[fx] < dep[fy]) std::swap(fx, fy);
        int fx1 = find(find, p[fx]);
        if (fx1 == fy) {
            ans = ((ans * siz[fx]) % mod) * siz[fy] % mod;
            merge(x, y);
        }
        else {
            std::cout << 0 << "\n";
            return ;
        }

    }
    std::cout << qpow(ans, mod - 2) << "\n";
}

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int t = 1;
    // std::cin >> t;

    while (t--) {
        solve();
    }
    return 0;
}