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


int solve(const int N, vector<int> p){
	vector<set<int> >g(N + 1);
	for(int i = 0; i < N - 1; ++i)
	{
		g[i + 2].insert(p[i]);
		g[p[i]].insert(i + 2);
	}

	vector<int> sub(N + 1);

	function<int(int, int)> subcalc = [&](int node, int par) -> int
	{
		sub[node] = 1;
		for(int next : g[node])
			if(next != par)
				sub[node] += subcalc(next, node);
		return sub[node];
	};
	
	function<int(int, int, int)> findcentroid = [&](int node, int par, int sz) -> int
	{
		for(int next : g[node])
		{
			if(next != par and sub[next] > sz/2)
				return findcentroid(next, node, sz);
		}

		return node;
	};

	
	int sz = N, root = 1;
	bool ans = false;
	int last = -500;
	while(!ans and sz)
	{
		subcalc(root, -1);
		int c = findcentroid(root, -1, sz);
		bool ok = ask(c);
		if(!ok)
		{
			int root = c;
			while(root > 1 and g[root].count(p[root - 2]))
			{
				root = p[root - 2];
			}
			if(root == c)break;
			sz = sub[root] - sub[c];

			auto it = g[p[c - 2]].find(c);
			if(it != g[p[c - 2]].end()) 
				g[p[c - 2]].erase(it);

			it = g[c].find(p[c - 2]);
			if(it != g[c].end())
				g[c].erase(it);
		}
		else
		{
			last = c;
			if(!g[c].size())
				return c;
			

			int child = -1;
			for(int next : g[c])
			{
				if(next > c)child = next;
			}

			if(child == -1)break;

			bool okc = ask(child);
			if(okc)
			{
				last = child;
				root = child;
				sz = sub[child];
				auto it = g[c].find(child);
				if(it != g[c].end())g[c].erase(it);
				it = g[child].find(c);
				if(it != g[child].end())g[child].erase(c);
			}
			else
			{
				if(g[c].size() <3)
					break;
				
				int child2 = -1;
				for(int next : g[c])
				{
					if(next != p[c - 2] and next != child)
					{
						child2 = next;
					}
				}

				root = child2;
				sz = sub[child2];

				auto it = g[c].find(child2);
				if(it != g[c].end())
					g[c].erase(it);

				it = g[child2].find(c);
				if(it != g[child2].end())
					g[child2].erase(c);
				
			}
		}
	}
	return last;


}