#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define dbg(a,b,c,d) cerr<<a<<"  "<<b<<"  "<<c<<"  "<<d<<endl;
#define kill(a) {cout<<a<<endl;continue;}
#define KILL(a) {cout<<a<<endl;return 0;}
#define debug cerr<<"Error Found"<<endl;
#define mem(a,b) memset(a,b,sizeof(a))
#define lcm(a, b) (a/__gcd(a,b))*b
#define w(t) cin>>t;while(t--)
#define pi  2 * acos(0.0)
#define endl "\n"
int t, cs = 0;
const int mxn = 2e5 + 3, mod = 1e9 + 7;
pair<int,int>mx_path;
vector<int>adj[mxn];
bool vis[mxn];
int dis[mxn];
int tot_dis, ans;
void find_tot_dis(int n, int par)
{
    for(auto i:adj[n])
    {
        if(i == par)continue;
        find_tot_dis(i, n);
        if(vis[i])dis[n] += dis[i] + 1, vis[n] = true;
    }
}
void dfs(int n, int par, int dis)
{
    if(vis[n])mx_path = max(mx_path, make_pair(dis, n));
    for(auto i:adj[n])if(i != par)dfs(i, n, dis + 1);
}
void DFS(int n, int par, int dis)
{
    if(vis[n])ans = min(ans, tot_dis - dis);
    for(auto i:adj[n])
    {
        if(i == par)continue;
        DFS(i, n, dis + 1);
    }
}
int32_t main()
{
    //fast;
    w(t)
    {
        int n;
        cin >> n;
        int root = 0;
        ans = 2e9;
        for(int i = 1, a; i <= n; i++)
        {
            adj[i].clear();
            vis[i] = dis[i] = 0;
            cin >> a;
            if(a)vis[i] = true, root = i;
        }

        for(int i = 1; i < n; i++)
        {
            int a, b;
            cin >> a >> b;
            adj[a].push_back(b), adj[b].push_back(a);
        }
        if(!root)kill(0);
        find_tot_dis(root, -1);
        tot_dis = dis[root] * 2;
        mx_path = make_pair(-1, 1);
        dfs(root, -1, 0);
        DFS(mx_path.second, -1, 0);
        cout << ans << endl;
    }
}