#include<bits/stdc++.h>

using namespace std;

#define endl "\n"

typedef long long ll;

const int N = 1e6 + 100;

vector<int>nx[N];
ll fa[N],fr[N],d[N],si[N];

void dfs(int be, int ne,int f)
{
	d[ne] = f;
	for (auto i : nx[ne])
	{
		if (be == i)
		{
			continue;
		}
		fr[i] = ne;
		dfs(ne, i,f+1);
	}
}

int find(int x)
{
	if (x != fa[x])
	{
		fa[x] = find(fa[x]);
	}
	return fa[x];
}

void hb(int x, int y)
{
	int a = find(x);
	int b = find(y);
	if (d[a] < d[b])
	{
		swap(a, b);
	}
	fa[a] = b;
	si[b] += si[a];
}

ll P = 998244353;

ll qp(ll a, ll b)
{
	ll an = 1;
	for (a %= P; b; a = a * a % P, b >>= 1)
	{
		if (b & 1)
		{
			an = an * a % P;
		}
	}
	return an;
}

int main()
{
	int n;
	cin >> n;
	fr[1] = 1;
	for (int i = 1; i <= n; i++)
	{
		fa[i] = i;
		si[i] = 1;
	}
	vector<pair<int, int>>vr(n-1);
	for (auto &[a,b]:vr)
	{
		cin >> a >> b;
	}
	for (int i = 2; i <= n; i++)
	{
		int a, b;
		cin >> a >> b;
		nx[a].push_back(b);
		nx[b].push_back(a);
	}
	dfs(-1, 1,1);
	fr[1] = 1;
	ll an = 1;
	for (auto& [a, b] : vr)
	{
		int faa = find(a);
		int fab = find(b);
		if (find(fr[faa]) == fab || find(fr[fab] == faa))
		{
			an = an * si[faa]%P*si[fab] % P;
			hb(faa, fab);
		}
		else
		{
			cout << 0 << endl;
			return 0;
		}
	}
	cout << qp(an,P-2) << endl;
	return 0;
}