#include <bits/stdc++.h>
#define int long long
using namespace std;
typedef long long ll;
const int maxn=1e6+5;
const int mod=998244353;
vector <int> mp[maxn];
int l[maxn],r[maxn];
int fa[maxn],siz[maxn];
long long a,b,p;
long long quickPower(long long a,long long b,long long p)
{
    long long ans=1,base=a;
    while (b>0)
    {
        if(b&1==1){
            ans*=base;
            ans%=p;
        }
        base*=base;
        base%=p;
        b>>=1;
    }
    return ans;
}
void dfs(int u,int f)
{
    fa[u]=f;
    for(auto v:mp[u])
    {
        if(v!=f)
        {
            dfs(v,u);
        }
    }
}
struct BCJ
{
    int fa[maxn];
    void init(int n)
    {
        for(int i=1;i<=n;i++)
        {
            fa[i]=i;
            siz[i]=1;
        }
    }
    int findfa(int x)
    {
        if(x==fa[x])
        {
            return x; 
        }
        return fa[x]=findfa(fa[x]);
    }
    void merge(int a,int b)
    {
        fa[a]=findfa(b);
        siz[b]+=siz[a];
    }
}bcj;
signed main()
{
    int n;
    cin>>n;
    for(int i=1;i<n;i++)
    {
        cin>>l[i]>>r[i];
    }
    for(int i=1;i<n;i++)
    {
        int u,v;
        cin>>u>>v;
        mp[u].push_back(v);
        mp[v].push_back(u);
    }
    bcj.init(n);
    dfs(1,1);
    int cnt=1;
    for(int i=1;i<n;i++)
    {
        if(bcj.findfa(l[i])==bcj.findfa(r[i]))
        {
            cout<<"0\n";
            return 0;
        }
        if((bcj.findfa(fa[bcj.findfa(l[i])])==bcj.findfa(r[i]))||(bcj.findfa(fa[bcj.findfa(r[i])])==bcj.findfa(l[i])))
        {
            cnt=cnt*siz[bcj.findfa(l[i])]%mod*siz[bcj.findfa(r[i])]%mod;
            bcj.merge(bcj.findfa(l[i]),bcj.findfa(r[i]));
        }   
        else 
        {
            cout<<"0\n";
            return 0;
        }
    }
    //cout<<cnt<<"\n";
    cout<<quickPower(cnt,mod-2,mod)<<"\n";
    return 0;
}