#include <iostream>
#include <fstream>
#include <vector>
#include <limits.h>

using namespace std;

class Node{

	public:vector<int> neighbors;
};

int minimum(int a, int b, int *which)
{
	if (a < b)
	{
		*which = 1;
		return a;
	}
	else
	{
		*which = 2;
		return b;
	}
}

int LCA(int node1, int node2, vector<int> &path, vector<int> &levels)
{
	int min = INT_MAX - 1;
	int ok = 0;
	int node = -1;
	int which;

	for (int i = 0; i < path.size(); i++)
	{
		if (path.at(i) == node1 || path.at(i) == node2)
		{
			if (ok == 0)
			{
				ok = 1;
				min = minimum(levels.at(i), min, &which);

				if (which == 1)
					node = path.at(i);

			}
			else if (ok == 1)
			{
				min = minimum(levels.at(i), min, &which);

				if (which == 1)
					node = path.at(i);

				break;
			}
		}

		if (ok == 1)
		{
			min = minimum(levels.at(i), min, &which);
			
			if (which == 1)
					node = path.at(i);

		}

	}

	return node;

}

void DFS(Node graph[], int node, int level, bool visited[], vector<int> &path, vector<int> &levels)
{
	visited[node] = true;
	path.push_back(node);
	levels.push_back(level);

	for (int neighbor : graph[node].neighbors)
	{
		if (visited[neighbor] == false)
		{
			DFS(graph, neighbor, level + 1, visited, path, levels);
			path.push_back(node);
			levels.push_back(level);
		}
	
	}

}


int main(int argc, char const *argv[])
{
	ifstream read("lca.in");
	ofstream write("lca.out");
	
	int N, M;

	read >> N >> M;
	
	Node graph[N + 1]; 
	bool visited[N + 1];
	vector<int> path;
	vector<int> levels;

	int father;
	for (int i = 2; i <= N; i++)
	{
		read >> father;
		graph[father].neighbors.push_back(i);
		graph[i].neighbors.push_back(father);
	}

	DFS(graph, 1, 0,visited, path, levels);
	int node1, node2;

	for (int i = 0; i < M; i++)
	{
		read >> node1 >> node2;
		write << LCA(node1, node2, path, levels) << '\n';
	}



	read.close();
	write.close();

	return 0;
}