#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N = 2e5 + 10;
const ll MOD = 1e9 + 7;

int root, cnt, mxlen;

vector<int> v(N), dist(N), g[N];

void dfs(int vertex, int par){
  for (auto child : g[vertex]){
    if (child == par) continue;
    dfs(child, vertex);
    v[vertex] = max(v[vertex], v[child]);
  }
}
void dfs2(int vertex, int par, int cur) {
  mxlen = max(mxlen, cur);
  cnt++;
  dist[vertex] = cur;
  for(auto child : g[vertex]) {
    if (child == par) continue;
    if(v[child]) {
      dfs2(child, vertex, cur + 1);
    }
  }
}

void solve()
{
  for(int i = 0; i < N; i++) {
    g[i].clear();
    dist[i] = 0;
    v[i] = 0;
    root = mxlen = cnt = 0;
  }
  int n;
  cin >> n;
  int root = 0;
  for(int i = 1; i <= n; i++) {
    cin >> v[i];
    if(v[i] == 1) {
      root = i;
    }
  }
  for(int i = 1; i < n; i++) {
    int u, v;
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
  }

  dfs(root, 0);
  dfs2(root, 0, 0);

  int ans = (cnt - 1) * 2, mx = 0;
  for(int i = 1; i <= n; i++) {
    if(dist[i] > mx) {
      root = i;
      mx = dist[i];
    }
  }
  dfs2(root, 0, 0);
  ans -= mxlen;

  cout << ans << endl;
}

int main()
{
  ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);

  int t;
  cin >> t;
  while(t--){
    solve();
  }
}