#define _CRT_SECURE_NO_WARNINGS
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0) 
#include<unordered_map>
#include<unordered_set>
#include<bits/stdc++.h>
#include<array>
using namespace std;
typedef long long ll;
typedef pair<ll, ll>pi;
#define int ll
#define X first
#define Y second
#define fer(i,a,n) for(ll i=a;i<=n;i++)
#define ref(i,n,a) for(ll i=n;i>=a;i--)
#define endl '\n'
#define mem(a,x) memset(a,x,sizeof a)
#define ac IO;int t;cin>>t;while(t--)solve()
#define AC signed main(){IO;solve();}
#define NO {cout<<"No"<<endl;return;}
#define YES {cout<<"yes"<<endl;return;}
#define re(a) {cout<<a<<endl;return;}
#define all(v) v.begin(),v.end()
//ofstream fout("out.txt", ios::out);
//ifstream fin("in.txt", ios::in);
//#define cout fout
//#define cin fin
//--------------------瑞神神中神--------------------

const int N = 1e6 + 10;
vector<int>e[N], v;
int dep[N];
int n;

void init()
{
	fer(i, 1, n)
	{
		e[i].clear();
		dep[i] = 0;
	}
	v.clear();
}

void dfs1(int u)
{
	if (!e[u].size())
	{
		dep[u] = 1;
		return;
	}
	for (int v : e[u])
	{
		dfs1(v);
		dep[u] = max(dep[u], dep[v] + 1);
	}
}

void dfs(int u, int dis)
{
	if (!e[u].size())
	{
		v.emplace_back(dis);
		return;
	}
	int mv = 0;
	for (int v : e[u])
	{
		if (dep[mv] < dep[v])
		{
			mv = v;
		}
	}
	dfs(mv, dis + 1);
	for (int v : e[u])
	{
		if (v == mv)continue;
		dfs(v, 1);
	}
}

void solve()
{
	cin >> n;
	init();
	fer(i, 2, n)
	{
		int x;
		cin >> x;
		e[x].emplace_back(i);
	}
	dfs1(1);
	dfs(1, 1);
	int ans = v.size(), sum = ans, i = 0;
	sort(all(v));
	while (i < v.size())
	{
		int j = i;
		while (j < v.size() - 1ll && v[j + 1] == v[i])j++;
		sum -= (j - i + 1);
		int res = sum + v[i];
		ans = min(ans, res);
		i = j + 1;
	}
	cout << ans << endl;
}

signed main()
{
	ac;
}