#include <fstream>
#include <vector>

using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

const int LOGN = 20;
const int NMAX = 100005;

int N, M;
int firstAp[NMAX], nivel[NMAX];

vector <int> son[NMAX];

int lg[NMAX];
vector <int> rmq[LOGN];

void DFS(int node)
{
	firstAp[node] = rmq[0].size();
	rmq[0].push_back(node);

	for(int i = 0; i < son[node].size(); i++)
        {
            int fiu = son[node][i];

            nivel[fiu] = nivel[node] + 1;
            DFS(fiu);

            rmq[0].push_back(node);
        }
}

int GetMin(int x, int y)
{
	if(nivel[x] < nivel[y])
        return x;

	return y;
}

void RMQ()
{
	for(int i = 1; i < LOGN; i++)
        {
            if ((1 << i) > rmq[0].size())
                break;

            for(int j = 0; j < rmq[0].size(); j++)
                {
                    if (j + (1 << i) > rmq[0].size())
                        break;

                    rmq[i].push_back(GetMin(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]));
                }
        }
}

int QueryRMQ(int x, int y)
{
	x = firstAp[x];
	y = firstAp[y];

	if(x > y)
        swap(x, y);

    int lenght = y - x + 1;
	int k = 0;

	while((1 << k) <= lenght)
		k++;
	k--;

	return GetMin(rmq[k][x], rmq[k][y - (1 << k) + 1]);
}

int main()
{
	int x, y;

	fin >> N >> M;

	for(int i = 2; i <= N; i++)
        {
            fin >> x;
            son[x].push_back(i);
        }

	DFS(1);
	RMQ();

	for(int i = 1; i <= M; i++)
        {
            fin >> x >> y;
            fout << QueryRMQ(x, y) << '\n';
        }

	return 0;
}