#include <bits/stdc++.h>
using namespace std;

const int maxn = 2e6 + 5;

int ans, K;
int rt[maxn], son[maxn], fa[maxn];
int top[maxn];

struct trie
{
	struct trinode
	{
		int ls, rs;
		int siz, lz;
        char dep;
	}t[2500005];
	int stk[2500005], tp, cnt;
	
	inline int newnod(int d)
	{
		int x = tp ? stk[tp--] : ++cnt;
		t[x].dep = d; return x;
	}
	inline void recycle(int x)
	{
		stk[++tp] = x;
		t[x].ls = t[x].rs = t[x].siz = t[x].dep = t[x].lz = 0;
	}
	
	inline void pushup(int k) { t[k].siz = t[t[k].ls].siz + t[t[k].rs].siz; }
	inline void upd(int k, int d) { t[k].lz ^= d; if (t[k].dep && ((d >> (t[k].dep - 1)) & 1)) swap(t[k].ls, t[k].rs); }
	inline void pushdown(int k) { if (t[k].lz) upd(t[k].ls, t[k].lz), upd(t[k].rs, t[k].lz), t[k].lz = 0; }
	
	int query(int k, int dep)
	{
		if (!k || !dep) return 0;
		pushdown(k);
		if (t[t[k].ls].siz == (1 << (dep - 1))) return (1 << (dep - 1)) + query(t[k].rs, dep - 1);
		else return query(t[k].ls, dep - 1);
	}
	
	int merge(int a, int b, int dep)
	{
		if (!a || !b) return a ^ b;
		if (!dep)
		{
			t[a].siz |= t[b].siz;
			recycle(b); return a;
		}
		pushdown(a), pushdown(b);
		t[a].ls = merge(t[a].ls, t[b].ls, dep - 1);
		t[a].rs = merge(t[a].rs, t[b].rs, dep - 1);
		recycle(b); pushup(a); return a;
	}
	
	void insert(int &k, int dep, int x)
	{
		if (!k) k = newnod(dep);
		if (!dep) return t[k].siz = 1, void();
		pushdown(k);
		if ((x >> (dep - 1)) & 1) insert(t[k].rs, dep - 1, x);
		else insert(t[k].ls, dep - 1, x);
		pushup(k);
	}
}T;

void work()
{
	int n; cin >> n; T.cnt = T.tp = K = 0;
	while ((1 << K) <= n) K++;
    for (int i = 1; i <= n; i++) son[i] = rt[i] = 0;
	for (int i = 2; i <= n; i++) cin >> fa[i];
    for (int i = n; i > 1; i--)
    {
        rt[i]++;
        if (rt[i] > rt[son[fa[i]]]) son[fa[i]] = i;
    }
    for (int i = 1; i <= n; i++)
    {
        if (i > 1 && i == son[fa[i]]) top[i] = top[fa[i]];
        else top[i] = i;
    }
    for (int i = 1; i <= n; i++) rt[i] = i;
    sort(rt + 1, rt + n + 1, [&](int x, int y) { return top[x] == top[y] ? x < y : top[x] < top[y]; });
    for (int i = 1; i <= n; i++) top[i] = rt[i], rt[i] = son[i] = 0;
    for (int i = n; i; i--)
    {
        int u = top[i];
        T.insert(rt[u], K, son[u]); son[u] = T.query(rt[u], K);
        if (u > 1)
        {
            if (rt[fa[u]]) T.upd(rt[fa[u]], son[u]);
            if (son[fa[u]]) T.upd(rt[u], son[fa[u]]);
            son[fa[u]] ^= son[u], rt[fa[u]] = T.merge(rt[fa[u]], rt[u], K);
        }
    }
    ans ^= son[1];
	for (int i = 1; i <= T.cnt; i++) T.recycle(i);
}

int main()
{
	ios::sync_with_stdio(false), cin.tie(0);
	
	int T; cin >> T;
	while (T--) work();
	cout << ans;
	return 0;
}