#include <bits/stdc++.h>
using namespace std;

const int Maxn = 1000500;

int deg[Maxn], fa[Maxn];
int n;

void solve(){
	cin >> n;
	for (int i = 1; i <= n; i++)
		deg[i] = 0;
	for (int i = 2; i <= n; i++)
		cin >> fa[i], deg[fa[i]]++;
	queue <int> que;
	for (int i = 1; i <= n; i++)
		if (deg[i] == 0) que.push(i);
	int ret = que.size();
	for (int it = 0; que.size(); it++){
		ret = min(ret, (int) que.size() + it);
		vector <int> vec;
		while (que.size()){
			int u = que.front(); que.pop();
			deg[fa[u]]--;
			if (deg[fa[u]] == 0) vec.push_back(fa[u]);
		}
		for (auto item : vec) que.push(item);
	}
	cout << ret << endl;
}

int main(){
	ios :: sync_with_stdio(false), cin.tie(0);
	int T;
	for (cin >> T; T--; solve());
	return 0;
}