#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T>inline void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T>inline void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

bool me;

const int maxn = 2000010;
const int maxm = maxn * 2;
const int B = 21;
const int msk = 1 << 30;
const int inh = 1 << 29;

int n, da[maxn], ans, rt[maxn], son[maxm][2], tot, lz[maxm], stk[25], nd[maxn], sum[maxn];
int head[maxn], nxt[maxn], to[maxn], hson[maxn], ct, buc[maxm], top, stop;
tuple<int, int, int, int> zhan[25];
bitset<maxm> f;
bitset<maxn> vis;

void add(int u, int v) {
  to[++ct] = v, nxt[ct] = head[u], head[u] = ct;
}

int nnd() {
  int u = top ? buc[top--] : ++tot;
  son[u][0] = son[u][1] = lz[u] = 0;
  return f[u] = false, u;
}

void down(int u, int d) {
  if (!u || !lz[u]) return;
  if (lz[u] >> d & 1) swap(son[u][0], son[u][1]);
  if (son[u][0]) lz[son[u][0]] ^= lz[u];
  if (son[u][1]) lz[son[u][1]] ^= lz[u];
  lz[u] = 0;
}

int merge(int u, int v) {
  int p = B;
  zhan[p] = make_tuple(u, v, 0, 0);
  while (p <= B) {
    auto [u, v, w, res] = zhan[p];
    if (!u || !v) {
      zhan[p] = make_tuple(u, v, w, u ^ v);
      p++;
    } else if (p == 0) {
      buc[++top] = v, zhan[p] = make_tuple(u, v, w, u);
      p++;
    } else if (w == 0) {
      down(u, p - 1), down(v, p - 1);
      zhan[p - 1] = make_tuple(son[u][0], son[v][0], 0, 0);
      zhan[p] = make_tuple(u, v, 1, 0);
      p--;
    } else if (w == 1) {
      son[u][0] = get<3>(zhan[p - 1]);
      zhan[p - 1] = make_tuple(son[u][1], son[v][1], 0, 0);
      zhan[p] = make_tuple(u, v, 2, 0);
      p--;
    } else {
      son[u][1] = get<3>(zhan[p - 1]);
      buc[++top] = v;
      f[u] = f[son[u][0]] & f[son[u][1]];
      zhan[p] = make_tuple(u, v, 3, u);
      p++;
    }
  }
  return get<3>(zhan[B]);
}

void ins(int u, int x) {
  stk[B] = u;
  per (i, B - 1, 0) {
    down(u, i);
    if (!son[u][x >> i & 1]) son[u][x >> i & 1] = nnd();
    u = son[u][x >> i & 1], stk[i] = u;
  }
  f[stk[0]] = 1;
  rep (i, 1, B - 1) f[stk[i]] = f[son[stk[i]][0]] & f[son[stk[i]][1]];
}

int qry(int u) {
  int res = 0;
  per (i, B - 1, 0) {
    down(u, i);
    if (f[son[u][0]]) res ^= (1 << i), u = son[u][1];
    else u = son[u][0];
  }
  return res;
}

void dfs1(int u) {
  da[u] = 1, hson[u] = 0;
  for (int i = head[u]; i; i = nxt[i]) {
    int v = to[i];
    dfs1(v), da[u] += da[v];
    if (da[v] > da[hson[u]]) hson[u] = v;
  }
}

void simugetson() {
  nd[stop = 1] = 1;
  while (stop) {
    int u = nd[stop];
    if (!lz[u]) {
      lz[u] = head[u], da[u] = 1, hson[u] = 0;
      if (!lz[u]) stop--;
      else nd[++stop] = to[lz[u]];
    } else {
      int v = to[lz[u]];
      da[u] += da[v];
      if (da[v] > da[hson[u]]) hson[u] = v;
      lz[u] = nxt[lz[u]];
      if (!lz[u]) stop--;
      else nd[++stop] = to[lz[u]];
    }
  }
}

void simudfs() {
  nd[stop = 1] = 1;
  while (stop) {
    int u = nd[stop];
    vis[u] = 1;
    if (!hson[u]) {
      rt[u] = nnd(), ins(rt[u], 0), da[u] = 1;
      stop--;
    } else if (hson[u] & inh) {
      hson[u] ^= inh;
      rt[u] = rt[hson[u]];
      sum[u] = da[hson[u]], lz[rt[u]] ^= da[hson[u]];
      hson[u] = msk ^ head[u];
      while ((hson[u] ^ msk) && vis[to[hson[u] ^ msk]]) hson[u] = nxt[hson[u] ^ msk] ^ msk;
      if (hson[u] == msk) {
        lz[rt[u]] ^= sum[u], ins(rt[u], sum[u]), da[u] = qry(rt[u]);
        stop--;
        continue;
      }
      nd[++stop] = to[hson[u] ^ msk];
    } else if (hson[u] & msk) {
      int v = to[hson[u] ^ msk];
      sum[u] ^= da[v], lz[rt[v]] ^= da[v], rt[u] = merge(rt[u], rt[v]);
      hson[u] = nxt[hson[u] ^ msk] ^ msk;
      while ((hson[u] ^ msk) && vis[to[hson[u] ^ msk]]) hson[u] = nxt[hson[u] ^ msk] ^ msk;
      if (hson[u] == msk) {
        lz[rt[u]] ^= sum[u], ins(rt[u], sum[u]), da[u] = qry(rt[u]);
        stop--;
        continue;
      }
      nd[++stop] = to[hson[u] ^ msk];
    } else {
      hson[u] |= inh, nd[++stop] = hson[u] ^ inh;
    }
  }
}

void work() {
  cin >> n, ct = tot = top = 0;
  rep (i, 1, n) rt[i] = head[i] = lz[i] = 0, vis.reset(i);
  rep (i, 2, n) cin >> da[i], add(da[i], i);
  simugetson(), simudfs();
  ans ^= da[1];
}

bool mb;

int main() {
  cerr << (&me - &mb) / 1048576. << '\n';
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  int t; cin >> t;
  while (t--) work();
  cout << ans << '\n';
}