#include <bits/stdc++.h>
#define all(x) begin(x), end(x)
#define rep(i, l, r) for (int i = (l), i##end = (r); i <= i##end; ++i)
#define per(i, l, r) for (int i = (l), i##end = (r); i >= i##end; --i)
#ifdef memset0
#define log(...) fprintf(stderr, __VA_ARGS__)
#else
#define log(...) (void(0))
#define endl '\n'
#endif
using namespace std;
using ll = long long;
using lf = long double;
using ull = unsigned long long;
const int N = 1e6;
int T, n, a[N + 10];
int u, v;
int mn1[N + 10], mn2[N + 10], ans;
vector<int> e[N + 10];
void dfs(int x, int fa, int d) {
  mn1[x] = d - a[x];
  mn2[x] = d + a[x];
  for (int i : e[x])
    if (i != fa) {
      dfs(i, x, d + 1);
      ans = min(ans, mn1[x] + mn2[i] - (d << 1) + 1);
      ans = min(ans, mn2[x] + mn1[i] - (d << 1) + 1);
      mn1[x] = min(mn1[x], mn1[i]);
      mn2[x] = min(mn2[x], mn2[i]);
    }
}
int main() {
#ifdef memset0
  freopen("J.in", "r", stdin);
#endif
  cin.tie(0)->sync_with_stdio(0);
  cin >> T;
  while (T--) {
    cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = 1; i <= n; ++i) vector<int>().swap(e[i]);
    for (int i = 1; i < n; ++i) {
      cin >> u >> v;
      e[u].push_back(v), e[v].push_back(u);
    }
    ans = 1;
    dfs(1, 0, 1);
    cout << ans << "\n";
  }
}