#include <bits/stdc++.h>

using namespace std;

#define ll long long

const int mod = 998244353;
const ll inf = 1e18;

void solve() {
  int n;
  cin >> n;
  vector<int> p(n + 1);
  for (int i = 2; i <= n; i++) cin >> p[i];

  auto wk2 = [&]() -> int {
    vector<int> c(n + 1), dep(n + 1);
    dep[1] = c[1] = 1;
    for (int i = 2; i <= n; i++) {
      dep[i] = dep[p[i]] + 1;
      c[dep[i]]++;
    }

    vector<int> b;
    for (int i = 1; i <= n; i++) {
      if (c[i] == 0) break;
      b.push_back(c[i]);
    }
    sort(b.begin(), b.end());

    int ans = b.size();
    for (int i = 0; i < b.size(); i++) {
      ans = min(ans, b[i] + (int)b.size() - i - 1);
    }
    // int s1 = 0;
    // for (int i = 1; i <= n; i++) s1 += c[i] != 0;

    // vector<int> vis(n + 1);
    // vis[0] = 1;
    // vector<int> id(n);
    // iota(id.begin(), id.end(), 0);
    // sort(id.begin(), id.end(),
    //      [&](int x, int y) { return dep[x + 1] > dep[y + 1]; });

    // int ans = s1, s2 = 0;
    // for (int i = 0; i < n; i++) {
    //   int now = id[i] + 1;
    //   if (vis[now]) continue;
    //   s2++;
    //   while (vis[now] == 0) {
    //     vis[now] = 1;
    //     c[dep[now]]--;
    //     if (c[dep[now]] == 0) s1--;
    //     now = p[now];
    //   }
    //   ans = min(ans, s1 + s2);
    // }
    return ans;
  };

  auto wk1 = [&]() -> int {
    vector<int> du(n + 1);
    for (int i = 2; i <= n; i++) du[p[i]]++;

    queue<int> q;
    for (int i = 1; i <= n; i++) {
      if (du[i] == 0) {
        q.push(i);
      }
    }

    int ans = q.size(), c = 0;
    while (q.size()) {
      c++;
      int siz = q.size();
      while (siz--) {
        int now = q.front();
        q.pop();
        du[p[now]]--;
        if (du[p[now]] == 0) {
          q.push(p[now]);
        }
      }
      ans = min(ans, (int)q.size() + c);
    }
    return ans;
  };
  cout << wk1() << "\n";
  // cout << wk2() << "\n";
  // cout << min(wk1(), wk2()) << "\n";
}

signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout << fixed << setprecision(10);
  int t = 1;
  cin >> t;
  while (t--) solve();
  return 0;
}