#include<bits/stdc++.h>
#define pb push_back
using namespace std;
vector<vector<int> > sp;
vector<int> col;
int INF = 1e9;
int d = INF;

bool dfs(int v, int p){
    if(p != 0){
        if(col[v] != col[p]){
            d = p;
            return 0;
        }
    }
    for(auto i : sp[v]){
        if(i != p) dfs(i, v);
    }
}

int dfs1(int v, int p){
    cout << "vxod ";
    if(p != d){
        if(col[v] != col[p]){
            cout << "badaBOOM " << v + 1 << ' ' << col[v] << ' ' << p + 1 << ' ' << col[p] << ' ';
            return 0;
        }
    }
    cout << "!!!!!! ";
    for(int i = 0; i < sp[v].size(); i++){
        int to = sp[v][i];
        cout << v + 1 << ' ' << p + 1 << ' ' << to + 1 << '\n';
        if(to != p){
            dfs1(to, v);
        }
    }

}
/*
4
1 2
2 3
3 4
1 2 1 1
*/
int main(){
    int n;
    cin >> n;
    sp.resize(n);
    col.resize(n);
    for(int i = 0; i < n - 1; i++){
        int a, b;
        cin >> a >> b;
        a--, b--;
        sp[a].pb(b);
        sp[b].pb(a);
    }
    for(int i = 0; i < n; i++){
        cin >> col[i];
    }
    dfs(0, 0);
    //cout << d << endl;
    if(d == INF){
        cout << "YES" << endl;
        cout << 1;
    }
    else{
        bool ch = dfs1(d, d);
        if(!ch){
            cout << "NO";
        }
        else {
            cout << "YES" << endl;
            cout << d;
        }
    }
}