#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#define NMAX 100001

using namespace std;

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

//int M[2 * NMAX][22];
vector <int> v[NMAX], e, niv, poz;
vector < vector<int> > M;

void DF(int nod, int nivel)
{
    int vec, sz = v[nod].size(), i;
    e.push_back(nod);           //euler
    niv.push_back(nivel);       //nivel

    if(!poz[nod])               //prima pozitie a nodului in sirul euler
        poz[nod] = e.size() - 1;

    for(i=0; i<sz; ++i)
        if(!poz[v[nod][i]]){
            DF(v[nod][i], nivel + 1);

            e.push_back(nod);
            niv.push_back(nivel);
        }
}

int query(int x, int y)
{
    int k = log2(y - x + 1);

    if(niv[ M[x][k] ] < niv[ M[y - (1<<k) + 1][k] ])
        return e[ M[x][k] ];
    else return e[ M[y - (1<<k) + 1][k] ];
}

int main()
{
    int n, m, nod, vec, i, j;
    e.push_back(0);
    niv.push_back(0);

    f >> n >> m;
    poz = vector<int>(n + 1, 0);
    M = vector< vector<int> > (2 * n + 1, vector<int>(22, 0));
    for(nod=2; nod<=n; ++nod){          //Citire
        f>>vec;

        v[nod].push_back(vec);
        v[vec].push_back(nod);
    }

    DF(1, 0);                           //Drum euler

    for(i=1; i <= e.size(); ++i)        //RMQ init
        M[i][0] = i;
    for(j=1; (1<<j) <= e.size(); ++j)
        for(i=1; i <= e.size() - (1<<j) + 1; ++i)
            if(niv[ M[i][j - 1] ] < niv[ M[i + (1<<(j - 1))][j - 1] ])
                M[i][j] = M[i][j - 1];
            else
                M[i][j] = M[i + (1<<(j - 1))][j - 1];

    for(i=1; i<=m; ++i){                //Query
        f >> nod >> vec;

        nod = poz[nod];
        vec = poz[vec];
        if(nod > vec)
            swap(nod, vec);

        g << query(nod, vec) << '\n';
    }

    return 0;
}