#ifdef LOCAL
#include "stdafx.h"
#else
#include <bits/stdc++.h>
#define IL inline
#define LL long long
#define eb emplace_back
#define sz(v) ((int) (v).size())
#define me(f, x) memset(f, x, sizeof(f))
#define mc(f, g) memcpy(f, g, sizeof(g))
#define L(i, j, k) for (int i = (j); i <= (k); ++i)
#define R(i, j, k) for (int i = (j); i >= (k); --i)
#define FIO(FILE) freopen(FILE".in", "r", stdin), freopen(FILE".out", "w", stdout)
using namespace std;

using vi = vector<int>;
#endif

#ifdef _WIN32
using uint = unsigned;
#endif

struct u24 {
  unsigned short a;
  unsigned char b;

  constexpr u24 (uint x = 0) : a(x >> 8 & 65535), b(x & 255) {}

  operator uint() const {
    return (a << 8) + b;
  }

#define DEF(o) \
  u24 operator o (const u24 &rhs) const { return uint(*this) o uint(rhs); } 
#define DEF2(o) \
  bool operator o (const u24 &rhs) const { return uint(*this) o uint(rhs); }
#define DEF3(o) \
  u24& operator o##= (const u24 &rhs) { return *this = *this o rhs; }
#define DEF4(o) \
  u24& operator o () { return (*this += 1); } \
  u24 operator o (int) { u24 x = *this; *this += 1; return x; }

  DEF(+) DEF(-) DEF(*) DEF(/) DEF(%) DEF(^) DEF(|) DEF(&)

  DEF2(<) DEF2(>) DEF2(==) DEF2(<=) DEF2(>=) DEF2(!=)

  DEF3(+) DEF3(-) DEF3(*) DEF3(/) DEF3(%) DEF3(^) DEF3(|) DEF3(&)

  DEF4(++) DEF4(--)

  u24 operator +() const {
    return *this;
  }
  u24 operator -() const {
    return -uint(*this);
  }

  u24 operator ~() const {
    return ~uint(*this);
  }

  bool operator !() const {
    return !a && !b;
  }
};

std::istream& operator >> (std::istream &is, u24 &x) {
  static uint x_;
  is >> x_;
  x = x_;
  return is;
}

std::ostream& operator << (std::ostream &os, const u24 &x) {
  os << (uint)(x);
  return os;
}

constexpr int N = 2e6 + 9;
constexpr int LG = 20;
int n;

int tot;
u24 hd[N];

struct {
  u24 v, nx;
} e[N];

int dfc;
u24 p[N], sz[N], son[N], seq[N];

void add_edge (int u, int v) {
  e[++tot] = {v, hd[u]};
  hd[u] = tot;
}

int t_;
u24 p_[N], it_[N];

bitset<N * 2> f;
u24 g[N * 2], ch[N * 2][2], rt[N], cnt;

void thr (int x) {
  p_[++t_] = x;
}

int New () {
  int x = t_ ? p_[t_--] : ++cnt;
  f[x] = false;
  g[x] = ch[x][0] = ch[x][1] = 0;
  return x;
}

void up (int p) {
  f[p] = f[ch[p][0]] & f[ch[p][1]];
}

void pp (int p, int x, int d) {
  if (x >> d & 1) {
    swap(ch[p][0], ch[p][1]);
  }
  g[p] ^= x;
}

void down (int p, int d) {
  if (int x = g[p]) {
    if (ch[p][0]) {
      pp(ch[p][0], x, d - 1);
    }
    if (ch[p][1]) {
      pp(ch[p][1], x, d - 1);
    }
    g[p] = 0;
  }
}

void ins (int d, int x, u24 &p) {
  if (!p) {
    p = New();
  }
  if (d < 0) {
    f[p] = true;
    return;
  }
  down(p, d);
  ins(d - 1, x, ch[p][x >> d & 1]);
  up(p);
}

int qry (int d, int p) {
  if (!p) {
    return 0;
  }
  if (d < 0) {
    return 1;
  }
  down(p, d);
  if (f[ch[p][0]]) {
    return (1 << d) + qry(d - 1, ch[p][1]);
  } else {
    return qry(d - 1, ch[p][0]);
  }
}

int merge (int d, int x, int y) {
  if (!x || !y) {
    return x | y;
  }
  thr(y);
  if (d < 0) {
    return x;
  }
  down(x, d);
  down(y, d);
  ch[x][0] = merge(d - 1, ch[x][0], ch[y][0]);
  ch[x][1] = merge(d - 1, ch[x][1], ch[y][1]);
  up(x);
  return x;
}

uint ans;
u24 dp[N];

void slv () {
  cin >> n;
  tot = 0;
  L (i, 1, n) {
    hd[i] = 0;
  }
  L (i, 2, n) {
    cin >> p[i];
    add_edge(p[i], i);
  }
  R (u, n, 1) {
    sz[u] = 1;
    son[u] = 0;
    for (int i = hd[u], v; i; i = e[i].nx) {
      v = e[i].v;
      sz[u] += sz[v];
      if (sz[v] > sz[son[u]]) {
        son[u] = v;
      }
    }
  }
  L (i, 1, n) {
    it_[i] = hd[i];
  }
  p_[t_ = 1] = 1;
  seq[dfc = 1] = 1;
  while (t_) {
    int u = p_[t_];
    if (!it_[u]) {
      --t_;
      if (son[u]) {
        p_[++t_] = son[u];
        seq[++dfc] = son[u];
      }
      continue;
    }
    u24 v = e[it_[u]].v;
    it_[u] = e[it_[u]].nx;
    if (v == son[u]) {
      continue;
    }
    p_[++t_] = v;
    seq[++dfc] = v;
  }
  L (i, 1, n) {
    dp[i] = rt[i] = 0;
  }
  R (i, n, 1) {
    int u = seq[i];
    ins(LG, 0, rt[u]);
    pp(rt[u], dp[u], LG);
    int x = qry(LG, rt[u]);
    if (i == 1) {
      ans ^= x;
    }
    pp(rt[u], x, LG);
    if (p[u]) {
      dp[p[u]] ^= x;
      rt[p[u]] = merge(LG, rt[p[u]], rt[u]);
    }
  }
  t_ = cnt = 0;
}

int main () {
  ios::sync_with_stdio(0), cin.tie(0);
  int T;
  cin >> T;
  while (T--) {
    slv();
  }
  cout << ans << '\n';
}
// I love WHQ!