#include <fstream>
#include <iostream>
#include <cmath>
#include <vector>
using namespace std;

const int NMAX = 100001;
const int LMAX = 30;
vector<int> G[NMAX];

long long k, n, m;
int nivel[2 * NMAX], euler[2 * NMAX], prima_apar[NMAX]; // euler tur- 2*nr muchii

ifstream fin("lca.in");

ofstream fout("lca.out");

int lg[2 * NMAX + 1];
int rmq[2 * NMAX + 1][LMAX];

void createLog()
{
    lg[1] = 0;
    for (int i = 2; i <= 2 * NMAX; i++)
        lg[i] = lg[i / 2] + 1;
}

void preprocRMQ(int a[2 * NMAX], int n)
{
    for (int i = 0; i < n; i++)
        rmq[i][0] = a[i];

    for (int j = 1; (1 << j) <= n; j++)
        for (int i = 0; i + (1 << j) - 1 < n; i++)
            rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
}

int query(int x, int y)
{
    int k = lg[y - x + 1];
    return min(rmq[x][k], rmq[y - (1 << k) + 1][k]);
}

void parcurg(int nod, int niv_curent)
{
    k = k + 1;
    euler[k] = nod;
    nivel[k] = niv_curent;
    prima_apar[nod] = k;

    for (auto it : G[nod])
    {
        parcurg(it, niv_curent + 1);

        k = k + 1;
        euler[k] = nod;
        nivel[k] = niv_curent;
    }
}

int main()
{
    int x;
    createLog();
    fin >> n >> m;
    for (int i = 2; i <= n; i++)
    {
        fin >> x;
        G[x].push_back(i);
    }
    k = -1;
    parcurg(1, 0);
    // for (int i = 0; i <= k; i++)
    //     cout << euler[i] << " ";
    // cout << "\n";
    // for (int i = 0; i <= k; i++)
    //     cout << nivel[i] << " ";
    // cout << "\n";

    // for (int i = 1; i <= n; i++)
    //     cout << i << " " << prima_apar[i] << endl;
    // cout << endl;
    preprocRMQ(nivel, k);
    for (int i = 0; i < m; i++)
    {
        int x, y;
        fin >> x >> y;
        int px = prima_apar[x];
        int py = prima_apar[y];
        if (px > py)
        {
            int aux = px;
            px = py;
            py = aux;
        }
        int level = query(px, py);
        bool found = false;
        for (int j = px; j <= py && found == false; j++)
        {
            if (level == nivel[j])
            {
                fout << euler[j] << endl;
                found = true;
            }
        }
    }
    return 0;
}