#include <bits/stdc++.h>
#ifndef ONLINE_JUDGE
#include <bits/Bingbong.h>
#endif
using namespace std;
#define i64 long long
#define pi acos(-1)
void solve() {
  int n;
  cin >> n;
  vector<int> a(n + 1);
  vector<vector<int>> e(n + 1);
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i < n; i++) {
    int u, v;
    cin >> u >> v;
    e[u].push_back(v);
    e[v].push_back(u);
  }
  if (n == 1) {
    cout << 1;
    return;
  }
  int ans = 2e9;
  vector<vector<int>> dp(n + 1, vector<int>(3, 2e9));
  // 在结点 i 为根的子树下选择了 j 个点的最小和
  //  a[v]+dist(u,v)
  auto dfs = [&](auto &&self, int u, int fa) -> void {
    dp[u][1] = a[u];
    vector<int> vv;
    for (auto v : e[u]) {
      if (v == fa) continue;
      self(self, v, u);
      dp[u][1] = min(dp[u][1], dp[v][1] + 1);  // 这个+1是当前结点
      // 先考虑当前结点和子树中的某个点搭配
      dp[u][2] = min(dp[u][2], dp[v][1] + 1 - a[u]);
      dp[u][2] = min(dp[u][2], a[u] - dp[v][1] + 2);
      // 再考虑子树中两点结合
      vv.push_back(dp[v][1]);
    }
    sort(vv.begin(), vv.end(), [](int a, int b) { return a > b; });
    if (vv.size() >= 2) {
      dp[u][2] = min(dp[u][2], vv[0] - vv[1] + 1);
      dp[u][2] = min(dp[u][2], -vv[0] + vv[1] + 2);
    }
    dp[u][1]++;
    ans = min(ans, dp[u][2]);
  };
  dfs(dfs, 1, 0);
  // for (int i = 1; i <= n; i++) cout << dp[i][1] << " " << dp[i][2] << endl;
  cout << ans << endl;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  cin >> t;
  while (t--) solve();
  return 0;
}
/*
2
5
4 5 3 4 2
1 2
2 3
3 4
3 5
5
4 4 1 1 2
1 2
2 3
3 4
3 5
*/