#include <fstream>
#include <iostream>
#include <vector>
#include <cmath>

using namespace std;

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

const int NMAX = 1e5;
const int LOGMAX = 20;
vector<int> v[NMAX];
int nivel[2 * NMAX], euler[2 * NMAX], pos[NMAX];
int cnt;
int rmq[2 * NMAX][LOGMAX];

void preprocesare(int v[], int n) {
    for (int i = 0; i < n; i++) {
        rmq[i][0] = i;
    }
    for (int j = 1; j <= log2(n); j++) {
        for (int i = 0; i < n; i++) {
                if (i + (1 << j) <= n) {
                        if (nivel[rmq[i][j-1]] < nivel[rmq[i+(1 << (j - 1))][j-1]]) {
                            rmq[i][j] = rmq[i][j-1];
                        } else {
                            rmq[i][j] = rmq[i+(1 << (j - 1))][j-1];
                        }
                    //rmq[i][j] = min(rmq[i][j-1], rmq[i+(1 << (j - 1))][j-1]);
                }
        }
    }
}

int interogare(int x, int y) {
    if (x < y)
    {
        swap(x, y);
    }
    int putere = log2(y - x + 1);
    if (nivel[rmq[x][putere]] < nivel[rmq[y - (1 << putere) + 1][putere]]) {
        return euler[rmq[x][putere]];
    } else {
        return euler[rmq[y - (1 << putere) + 1][putere]];
    }
    //return min(rmq[x][putere], rmq[y - (1 << putere) + 1][putere]);
}

void parcurgere(int x, int nivel_curent) {
    euler[cnt] = x;
    nivel[cnt] = nivel_curent;
    cnt++;
    pos[x] = cnt;
    for (int i = 0; i < v[x].size(); i++) {
        parcurgere(v[x][i], nivel_curent + 1);
        euler[cnt] = x;
        nivel[cnt] = nivel_curent;
        cnt++;
    }
}

int main()
{
    int n, m;
    in >> n >> m;

    for (int i = 2; i <= n; i++) {
        int x;
        in >> x;
        v[x].push_back(i);
    }
    parcurgere(1, 0);
    preprocesare(euler, cnt);
    for (int i = 0; i < m; i++)
    {
        int x, y;
        in >> x >> y;
        cout << interogare(pos[x], pos[y]) << endl;
    }
    return 0;
}