#include<bits/stdc++.h>
#define IL inline
#define reg register
#define N 2000200
#define M 8000800
IL int read()
{
    reg int x=0;reg char ch=getchar();
    while(ch<'0'||ch>'9')ch=getchar();
    while(ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
    return x;
}

int n,ch[M][2],tot,tag[M],rt[N],sg[N],f[N],h[N];
std::bitset<M>full;

IL void pushdown(reg int x,reg int d)
{
    if(tag[x]&&~d)
    {
        tag[ch[x][0]]^=tag[x],tag[ch[x][1]]^=tag[x];
        if(tag[x]>>d&1)std::swap(ch[x][0],ch[x][1]);
        tag[x]=0;
    }
}

IL void pushup(reg int x){if(!full[x])full[x]=full[ch[x][0]]&full[ch[x][1]]&(ch[x][0]>0&&ch[x][1]>0);}

int merge(reg int x,reg int y,reg int d)
{
    if(!x||!y)return x|y;
    pushdown(x,d),pushdown(y,d);
    ch[x][0]=merge(ch[x][0],ch[y][0],d-1);
    ch[x][1]=merge(ch[x][1],ch[y][1],d-1);
    pushup(x);
    return x;
}

void insert(reg int &x,reg int k,reg int d)
{
    if(!x)x=++tot;
    if(d<0)return full[x]=1,void();
    reg int v=k>>d&1;
    pushdown(x,d),insert(ch[x][v],k^(v<<d),d-1),pushup(x);
}

int query(reg int x,reg int d)
{
    if(!x)return 0;
    pushdown(x,d);
    if(full[ch[x][0]])return (1<<d)|query(ch[x][1],d-1); 
    return query(ch[x][0],d-1);
}

int Merge(reg int x,reg int y,reg int dx,reg int dy)
{
    if(dx==dy)return merge(x,y,dx);
    if(!x)x=++tot;
    pushdown(x,dx);
    ch[x][0]=Merge(ch[x][0],y,dx-1,dy);
    return pushup(x),x;
}

int all,sum[N];

IL void work()
{
    n=read();
    for(reg int i=1;i<=n;++i)f[i]=sg[i]=rt[i]=h[i]=sum[i]=0;
    for(reg int i=0;i<=tot;++i)
        tag[i]=full[i]=ch[i][0]=ch[i][1]=0;
    tot=0;
    static int fa[N];
    for(reg int i=2;i<=n;++i)fa[i]=read();
    for(reg int v=n,u;v;--v)
    {
        insert(rt[v],0,h[v]);
        tag[rt[v]]^=sum[v];
        sg[v]=query(rt[v],h[v]);
        if(sg[v]>>h[v]&1)
        {
            ch[++tot][0]=rt[v],++h[v];
            pushup(rt[v]=tot);
        }
        if(v==1)break;
        u=fa[v],tag[rt[v]]^=sg[v],sum[u]^=sg[v];
        if(h[u]<h[v])std::swap(rt[u],rt[v]),std::swap(h[u],h[v]);
        if(h[u]==h[v]){rt[u]=merge(rt[u],rt[v],h[u]); continue;}
        rt[u]=Merge(rt[u],rt[v],h[u],h[v]);
        std::vector<int>Q;
        reg int p=rt[u];
        for(reg int i=h[u];i>h[v];--i)
        {
            Q.push_back(p),pushdown(p,i);
            if(i>h[v]+1)p=ch[p][0];
        }
        ch[p][0]=merge(ch[p][0],rt[v],h[v]);
        while(!Q.empty())pushup(Q.back()),Q.pop_back();
    }
    all^=sg[1];
}

main()
{
    for(reg int t=read();t--;work());
    printf("%d\n",all);
}