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

using namespace std;

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

const int NMAX = 100000 + 1;
const int LOGMAX = 18 + 1;

int n, m, nre;
int eticheta[NMAX], etichetat[NMAX], prima_aparitie[NMAX], lg2[2 * NMAX];
int rmq[LOGMAX][2 * NMAX];
vector <int> graf[NMAX];

void citeste() {
    f >> n >> m;
    int x;
    for (int i = 2; i <= n; i++) {
        f >> x;
        graf[x].push_back(i);
    }
}

void parcurgere_euleriana(int nod, int &e) {
    eticheta[nod] = ++e;
    int l = graf[nod].size(), fiu;
    rmq[0][++nre] = e;
    prima_aparitie[nod] = nre;
    etichetat[e] = nod;

    for (int i = 0; i < l; i++) {
        fiu = graf[nod][i];
        parcurgere_euleriana(fiu, e);
        rmq[0][++nre] = eticheta[nod];
    }
}

void initializeaza_rmq() {
    for (int i = 2; i <= nre; i++) lg2[i] = lg2[i / 2] + 1;
    int l;
    for (int i = 1; (1 << i) <= nre; i++)
        for (int j = 1; j <= nre - (1 << i) + 1; j++) {
            l = 1 << (i - 1);
            rmq[i][j] = min(rmq[i - 1][j], rmq[i - 1][j + l]);
        }
}

void LCA(int a, int b) {
    a = prima_aparitie[a];
    b = prima_aparitie[b];
    if (a > b) swap(a, b);
    int dif = b - a + 1;
    int l = lg2[dif];
    int l2 = dif - (1 << l);
    int rez =  min(rmq[l][a], rmq[l][a + l2]);
    rez = etichetat[rez];
    g << rez << '\n';
}

int main() {
    citeste();
    int e = 0;
    parcurgere_euleriana(1, e);
    initializeaza_rmq();
    int a, b;
    while(m--) {
        f >> a >> b;
        LCA(a, b);
    }
}