#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define db double
#define ldb long double
#define max(A,B) (A>B? A:B)
#define min(A,B) (A<B? A:B)
#define yes cout<<"Yes\n"
#define no cout<<"No\n"
#define pir(X) pair<X,X>
#define mpr(A,B) make_pair(A,B)
#define fr first
#define sc second
using namespace std;

const int mod=998244353;
int pls(int a,int b){
    if(a+b>=mod) return a+b-mod;
    if(a+b<0) return a+b+mod;
    return a+b;
}
int mul(int a,int b){
    return (ll)a*b%mod;
}
int qpow(int a,int b){
    int ret=1;
    while(b){
        if(b&1) ret=mul(ret,a);
        a=mul(a,a);
        b>>=1;
    }
    return ret;
}
int inv(int x){
    return qpow(x,mod-2);
}

const int N=1e6+10;
int n;
struct edge{
    int x,y;
}e1[N],e2[N];

struct UF_S{
    int fa[N],siz[N];
    int find(int x){
        if(x==fa[x]) return x;
        fa[x]=find(fa[x]);
        return fa[x];
    }
    bool mrg(int x,int y){
        x=find(x),y=find(y);
        if(x==y) return 0;
        if(siz[x]<siz[y]) swap(x,y);
        fa[y]=x,siz[x]+=siz[y];
        return 1;
    }
    void init(int n){
        for(int i=1;i<=n;i++) fa[i]=i,siz[i]=1;
    }
}s;

void fst_IO(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

int main(){
    fst_IO();
    cin>>n;
    s.init(n);
    for(int i=1;i<n;i++) cin>>e1[i].x>>e1[i].y;
    for(int i=1;i<n;i++) cin>>e2[i].x>>e2[i].y;
    int ans=1;
    for(int i=1;i<n;i++){
        int x=e1[i].x,y=e1[i].y;
        x=s.find(x),y=s.find(y);
        ans=mul(ans,inv(mul(s.siz[x],s.siz[y])));
        s.mrg(x,y);
    }
    cout<<ans<<'\n';
    return 0;
}