#include <cstdio>
#include <algorithm>
#include <vector>
#include <utility>
using namespace std;
const int N = 1e6 + 5, mod = 998244353;
inline long long fpow (long long a, long long b) {
    long long res = 1;
    while (b) {
        if (b & 1) res = res * a % mod;
        a = a * a % mod;
        b >>= 1;
    }
    return res % mod;
}
int n, S[N], siz[N], fa[N], dep[N];
long long inv[N];
pair <int, int> a[N];
vector <int> g[N];
int getf (int x) {return x == S[x] ? x : S[x] = getf(S[x]);}
void dfs (int u, int nfa) {
    fa[u] = nfa, dep[u] = dep[nfa] + 1;
    for (int v : g[u]) if (v != nfa) dfs(v, u);
}
int main() {
    scanf ("%d", &n);
    for (int i = 1; i < n; i++) scanf ("%d%d", &a[i].first, &a[i].second);
    for (int i = 1, u, v; i < n; i++) {
        scanf ("%d%d", &u, &v);
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(1, 0);
    for (int i = 1; i <= n; i++) S[i] = i, siz[i] = 1;
    for (int i = 1; i <= n; i++) inv[i] = fpow(i, mod - 2);
    long long ans = 1;
    for (int i = 1; i < n; i++) {
        int u = a[i].first, v = a[i].second;
        int x = getf(u), y = getf(v);
        if (x == y || (fa[x] != y && fa[y] != x)) {printf ("0\n"); return 0;}
        ans = ans * inv[siz[x]] % mod * inv[siz[y]] % mod;
        if (dep[x] > dep[y]) S[x] = y, siz[y] += siz[x];
        else S[y] = x, siz[x] += siz[y];
    }
    printf ("%lld\n", ans);
    return 0;
}