#include <fstream>
#include <vector>
#define NMAX 100000
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

/// euler - contine nodurile in reprezentarea euleriana
int n, m, parinte[NMAX + 5], first[NMAX + 5], height[NMAX + 5], log[2 * NMAX + 5];
vector<int> fii[NMAX + 5], euler;
int RMQ[18][2 * NMAX + 5];

void citireArbore();
void buildEuler(int nod, int h);
void buildRMQ();
int LCA(int x, int y);

int main(){
    citireArbore();

    buildEuler(1, 0);
    
    buildRMQ();

    int x, y;
    while(m--){
        fin >> x >> y;
        fout << LCA(x, y) << '\n';
    }

    fin.close();
    fout.close();
    return 0;
}

int LCA(int x, int y){
    x = first[x];
    y = first[y];
    if(x > y) swap(x, y);

    int p2 = log[y - x + 1];
    int len = 1 << p2;

    // vrem NODUL, NU inaltimea
    return (height[RMQ[p2][x]] < height[RMQ[p2][y - len + 1]] ? 
            RMQ[p2][x] : RMQ[p2][y - len + 1]);
}

void buildRMQ(){
    //! IMPORTANT: euler & RMQ sunt 0-indexed !
    //! RMQ contine NODURILE de inaltime minima pe intervalele coresp.
    int Ne = euler.size();
    for(int i = 0; i < Ne; i++)
        RMQ[0][i] = euler[i];
    
    for(int p = 1; (1 << p) <= Ne; p++){
        for(int i = 0; i < Ne; i++){
            RMQ[p][i] = RMQ[p - 1][i];
            int j = i + (1 << (p - 1));
            // vrem NODUL, NU inaltimea
            if(j < Ne)
                RMQ[p][i] = (height[RMQ[p][i]] < height[RMQ[p - 1][j]] ?
                             RMQ[p][i] : RMQ[p - 1][j]);
        }
    }

    log[1] = 0;
    for(int i = 2; i <= Ne; i++)
        log[i] = log[i >> 1] + 1;
}

void buildEuler(int nod, int h){
    height[nod] = h;
    first[nod] = euler.size();
    euler.push_back(nod);
    for(auto i : fii[nod]){
        buildEuler(i, h + 1);
        euler.push_back(nod);
    }
}

void citireArbore(){
    int x;
    /// nodul 1 este radacina
    fin >> n >> m;
    for(int i = 2; i <= n; i++){
        fin >> x;
        fii[x].push_back(i);
    }
}