#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][30], poz[NMAX];
vector <int> v[NMAX], e, niv;

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

    if(!poz[nod])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;
    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++) M[i][0]=i; //RMQ
    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;
}