#include<iostream>

#include<cstdio>

#include<cstring>

#include<string>

#include<algorithm>

#include<cmath>

#include<map>

#include<set>

#include<vector>

#include<stack>

#include<queue>

#pragma comment(linker, "/STACK:1024000000,1024000000")

#define ll long long



using namespace std;

const int INF=0x3f3f3f3f;

const int MOD=100000007;

const int N=500005;

int MAX[N][2],f[N];

int in[N],c[N];

int head[N],I;

vector<int>vt;

struct node

{

    int j,next;

}edge[N];

void add(int i,int j)

{

    edge[I].j=j;

    edge[I].next=head[i];

    head[i]=I++;

}

int dp(int x,int k)

{

    if(MAX[x][k]!=-1)

    return MAX[x][k];

    if(in[x]==0)

    return (MAX[x][k]=0);

    MAX[x][k]=0;

    int tmp=-INF,l=0;

    for(int t=head[x];t!=-1;t=edge[t].next)

    {

        int w=edge[t].j;

        MAX[x][k]+=(dp(w,0));

        if(dp(w,1)-dp(w,0)>tmp)

        {

            tmp=dp(w,1)-dp(w,0);

            l=w;

        }

    }

    if(k==0)

    {

        c[x]=l;

        MAX[x][k]+=(tmp+1);

    }

    return MAX[x][k];

}

void dfs(int x,int k)

{//cout<<x<<" "<<k<<endl;

    if(in[x]==0) return;

    if(k==0)

    vt.push_back(c[x]);

    for(int t=head[x];t!=-1;t=edge[t].next)

    {

        int w=edge[t].j;

        if(k==0&&c[x]==w)

        dfs(w,1);

        else

        dfs(w,0);

    }

}

int main()

{

    //freopen("data.in","r",stdin);

    int T;

    cin>>T;

    while(T--)

    {

        int n;

        cin>>n;

        memset(in,0,sizeof(in));

        memset(head,-1,sizeof(head));I=0;

        for(int i=2;i<=n;++i)

        {cin>>f[i];++in[f[i]];add(f[i],i);}

        memset(MAX,-1,sizeof(MAX));

        cout<<(dp(1,0)*1000)<<endl;

        vt.clear();

        dfs(1,0);

        sort(vt.begin(),vt.end());

        for(unsigned int i=0;i<vt.size();++i)

        {

            if(i>0) cout<<" ";

            cout<<vt[i];

        }cout<<endl;

    }

    return 0;

}