#include<iostream>
#include<vector>
#include<algorithm>
#include<utility>
#include<set>
#include<cmath>
using namespace std;
typedef long long ll;
const int inf = 1e9;
struct reroot{
vector<vector<int>> graph;
vector<int> vec, dp1, dp2;
int n;
reroot(int _n){
n = _n;
graph.resize(n + 1);
vec.resize(n + 1);
dp1.resize(n + 1);
dp2.resize(n + 1);
}
void add(int a, int b){
graph[a].push_back(b);
graph[b].push_back(a);
}
void set_1(int x){
vec[x] = 1;
}
void dfs1(int node, int parent){
if(vec[node]) dp1[node] = 0;
else dp1[node] = inf;
for(auto &x: graph[node]){
if(x == parent) continue;
dfs1(x, node);
dp1[node] = min(dp1[node], dp1[x] + 1);
}
}
void dfs2(int node, int parent, int up){
multiset<int> s;
s.insert(up + 1);
for(auto &x: graph[node]){
if(x == parent) continue;
s.insert(dp1[x] + 1);
}
dp2[node] = (*s.begin());
if(vec[node]) s.insert(0);
for(auto &x: graph[node]){
if(x == parent) continue;
s.erase(s.find(dp1[x] + 1));
dfs2(x, node, (*s.begin()));
s.insert(dp1[x] + 1);
}
}
void do_dp(){
dfs1(1, 1);
dfs2(1, 1, inf);
}
};
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
int t;
cin >> t;
while(t--){
int n;
cin >> n;
reroot zer(n), one(n);
for(int i = 1; i < n; i++){
int a, b;
cin >> a >> b;
zer.add(a, b);
one.add(a, b);
}
vector<int> vec(n + 1);
for(int i = 1; i <= n; i++){
cin >> vec[i];
if(vec[i] == 1) one.set_1(i);
else zer.set_1(i);
}
zer.do_dp();
one.do_dp();
int ans = 0;
for(int i = 1; i <= n; i++){
if(vec[i] == 1){
ans = max(ans, one.dp2[i]);
}
else{
ans = max(ans, zer.dp2[i]);
}
}
if(ans >= inf) cout << "-1\n";
else cout << ans << "\n";
}
}
// g++ -std=c++17 -Wall -Wextra -Wshadow -fsanitize=undefined -fsanitize=address -o run pD.cpp -g
