#include<bits/stdc++.h>
using namespace std;
const int MAX=1e6+6;
int r[MAX],n;//chudu
int fa[MAX];
vector<int> g1,g2;
void solve(){
    cin>>n;
    g1.clear(),g2.clear();
    memset(r,0,sizeof(int)*(n+1));

    for(int i=2;i<=n;++i){
        cin>>fa[i];
        r[fa[i]]++;
    }
    int ans=0,cnt=0;
    int lv=0;

    for(int i=1;i<=n;++i){
        if(r[i]==0){
            ans++;
            g1.push_back(i);
        }           
    }

    while(!g1.empty()){
        int num=0;
        cnt++;
        for(auto i=g1.begin();i!=g1.end();++i){
            r[fa[*i]]--;
            if(fa[*i]!=0&&r[fa[*i]]==0){
                num++;
                g2.push_back(fa[*i]);
            }            
        }
        ans=min(ans,cnt+num);
        g1=g2;
        g2.clear();
    }

    cout<<ans<<"\n";
}
int main(){
//   freopen("in.txt","r",stdin);
 //   freopen("out.txt","w",stdout);
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);

    int T;
    cin>>T;
    while(T--){
        solve();
    }
}