#include<bits/stdc++.h>
#include"testlib.h"
#include<atcoder/all>
using namespace std;
using ll = long long;

const ll Nmin = 2, Nmax = 200'000;
const ll Amin = 0, Amax = 1'000'000'000;

int main(){
    registerValidation();
    ll n = inf.readLong(Nmin,Nmax);
    inf.readEoln();
    for (int i = 0; i < n; i++){
        inf.readLong(Amin,Amax);
        if (i != n-1){
            inf.readSpace();
        }
        else {
            inf.readEoln();
        }
    }
    atcoder::dsu d(n);
    for (int i = 0; i < n-1; i++){
        ll u = inf.readLong(1,n);
        inf.readSpace();
        ll v = inf.readLong(1,n);
        inf.readEoln();
        u--, v--;
        inf.ensuref(!d.same(u,v),"graph must form a tree");
        d.merge(u,v);
    }
    inf.readEof();
}