#include <bits/stdc++.h>
using namespace std;
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  os << '{';
  string sep;
  for (const auto &x : v) os << sep << x, sep = ", ";
  return os << '}';
}
template <typename T, size_t size>
ostream &operator<<(ostream &os, const array<T, size> &arr) {
  os << '{';
  string sep;
  for (const auto &x : arr) os << sep << x, sep = ", ";
  return os << '}';
}
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
  return os << '(' << p.first << ", " << p.second << ')';
}
void dbg_out() { cerr << endl; }
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T) {
  cerr << ' ' << H;
  dbg_out(T...);
}
template <typename T1, typename T2>
bool maximize(T1 &a, const T2 &b) {
  if (a < T1(b)) {
    a = T1(b);
    return true;
  }
  return false;
}
void run_case() {
  int N;
  cin >> N;
  vector<int> A(N);
  for (auto &a : A) cin >> a;
  int Z = int(count(A.begin(), A.end(), 0));
  int H = Z / 2;
  if (H == 0 || Z == N) {
    cout << 0 << '\n';
    return;
  }
  vector<array<int, 2>> LR(N + 1, {0, 0});
  for (int i = 0, z = 0; i < N; i++)
    if (A[i] == 0) {
      z++;
    } else {
      if (z >= H) maximize(LR[A[i]][1], Z - z);
      if (z <= Z - H) maximize(LR[A[i]][0], z);
    }
  vector<bool> matched(N + 1, false);
  int answer = 0;
  for (int dim = 0; dim < 2; dim++) {
    vector<pair<array<int, 2>, int>> options(N);
    for (int a = 1; a <= N; a++)
      options[a - 1] = {{LR[a][dim], LR[a][!dim]}, a};
    sort(options.rbegin(), options.rend());
    priority_queue<pair<int, int>, vector<pair<int, int>>,
                   greater<pair<int, int>>>
        pq;
    for (int x = N, i = 0; x > 0; x--) {
      while (i < N && options[i].first[0] >= x) {
        if (!matched[options[i].second])
          pq.emplace(options[i].first[1], options[i].second);
        i++;
      }
      if (!pq.empty()) {
        auto top = pq.top();
        pq.pop();
        matched[top.second] = true;
        answer++;
      }
    }
  }
  answer = min(answer, H);
  cout << answer << '\n';
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int tests;
  cin >> tests;
  while (tests-- > 0) run_case();
}
