#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
template <typename T>
void ckmn(T& a, T b) {
  a = min(a, b);
}
template <typename T>
void ckmx(T& a, T b) {
  a = max(a, b);
}
void rd(int& x) { scanf("%i", &x); }
void rd(long long& x) { scanf("%lld", &x); }
void rd(char* x) { scanf("%s", x); }
void rd(double& x) { scanf("%lf", &x); }
void rd(string& x) { scanf("%s", &x); }
template <typename T1, typename T2>
void rd(pair<T1, T2>& x) {
  rd(x.first);
  rd(x.second);
}
template <typename T>
void rd(vector<T>& x) {
  for (T& i : x) rd(i);
}
template <typename T, typename... A>
void rd(T& x, A&... args) {
  rd(x);
  rd(args...);
}
template <typename T>
void rd() {
  T x;
  rd(x);
  return x;
}
int ri() {
  int x;
  rd(x);
  return x;
}
template <typename T>
vector<T> rv(int n) {
  vector<T> x(n);
  rd(x);
  return x;
}
template <typename T>
void ra(T a[], int n, int st = 1) {
  for (int i = 0; i < n; ++i) rd(a[st + i]);
}
template <typename T1, typename T2>
void ra(T1 a[], T2 b[], int n, int st = 1) {
  for (int i = 0; i < n; ++i) rd(a[st + i]), rd(b[st + i]);
}
template <typename T1, typename T2, typename T3>
void ra(T1 a[], T2 b[], T3 c[], int n, int st = 1) {
  for (int i = 0; i < n; ++i) rd(a[st + i]), rd(b[st + i]), rd(c[st + i]);
}
void re(vector<int> E[], int m, bool dir = 0) {
  for (int i = 0, u, v; i < m; ++i) {
    rd(u, v);
    E[u].push_back(v);
    if (!dir) E[v].push_back(u);
  }
}
template <typename T>
void re(vector<pair<int, T>> E[], int m, bool dir = 0) {
  for (int i = 0, u, v; i < m; ++i) {
    T w;
    rd(u, v, w);
    E[u].push_back({v, w});
    if (!dir) E[v].push_back({u, w});
  }
}
const int N = 200050;
vector<int> E[N];
int col[N], dp[N][2], diam;
void DFS(int u, int p) {
  int best[2] = {0, 0};
  if (col[u] == 1) best[0] = 1;
  if (col[u] == 2) best[1] = 1;
  for (int v : E[u])
    if (v != p) {
      DFS(v, u);
      ckmx(diam, best[0] + dp[v][0] - 1);
      ckmx(diam, best[1] + dp[v][1] - 1);
      ckmx(diam, best[0] + dp[v][1]);
      ckmx(diam, best[1] + dp[v][0]);
      if (col[u] == 0) {
        ckmx(best[0], dp[v][0]), ckmx(best[1], dp[v][1]);
      } else if (col[u] == 1) {
        ckmx(best[0], max(dp[v][1] + 1, dp[v][0]));
      } else if (col[u] == 2) {
        ckmx(best[1], max(dp[v][0] + 1, dp[v][1]));
      }
    }
  ckmx(diam, max(best[0], best[1]));
  dp[u][0] = best[0];
  dp[u][1] = best[1];
}
int main() {
  for (int t = ri(); t--;) {
    int n = ri();
    ra(col, n);
    for (int i = 1; i <= n; i++) E[i].clear();
    re(E, n - 1);
    diam = 0;
    DFS(1, 0);
    int ans = diam / 2 + 1;
    printf("%i\n", ans);
  }
  return 0;
}
