#include<bits/stdc++.h>
using namespace std;
#define ll unsigned long long
#define MID int mid=(l+r)>>1;
#define ls p<<1
#define rs p<<1|1
int n,d[1001000],p[1001000],vis[1001000];
vector<int>a;
void clr(){
	for(int i=0;i<=n;i++)vis[i]=d[i]=0;
	a.clear();
}
void solve(){
	clr();
	cin>>n;
	for(int i=2;i<=n;i++){
		cin>>p[i];
	}
	for(int i=n;i>=1;i--){
		d[p[i]]=max(d[p[i]],d[i]+1);
		vis[d[i]]++;
	}
	int ans=0x3f3f3f3f;
	for(int i=0;i<=n;i++){
		ans=min(ans,vis[i]+i);
	}
	cout<<ans<<endl;
}
int main(){
	ios::sync_with_stdio(false);cin.tie(0),cout.tie(0);
	int T;
	cin>>T;
	while(T--){
		solve();
	}	
}