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

#define ios ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define int long long
#define pb push_back
#define ff first
#define ss second
typedef pair<int, int> PII;
const int N = 1000007;
const int inf = 1e18;
const int mod = 1e9+7;
mt19937_64 rng(time(0));

vector<int>v[N];
int n;
void solve() {
    cin>>n;
    vector<int>d(n+5);
    for(int i=2;i<=n;i++){
        int x;
        cin>>x;
        d[x]++;
        v[i].pb(x);
    }
    int cnt=0;
    queue<PII>q;
    for(int i=1;i<=n;i++){
        if(!d[i]){
            q.push({i,0});
        }
    }
    int ans=q.size();
    int f=0;
    while(q.size()){
        auto t=q.front();
        if(t.ss!=f){
            int tt=q.size();
            ans=min(ans,tt+t.ss);
            f=t.ss;
        }
        if(v[t.ff].size()){
            d[v[t.ff][0]]--;
            if(!d[v[t.ff][0]]){
                q.push({v[t.ff][0],t.ss+1});
            }
        }
        q.pop();
    }
    cout<<ans<<'\n';
    for(int i=0;i<n+2;i++)v[i].clear();
}
signed main() {
    ios;
    int _ = 1;
    cin >> _;
    while (_--) {
        solve();
    }
    return 0;
}