#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#define MAX (1<<30)-1
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int n,m,cnt;
int euleriana[200004],niveluri[200004],poz_noduri[100001];
int rmq_dp[200005][30];
vector<int>adiacenta[100001];
void citire()
{
    f >> n >> m;
    for(int i = 2;i<=n;i++)
    {
        int tata;
        f >> tata;
        adiacenta[tata].push_back(i);
    }
}
void parcurgere_euleriana(int nod,int nivel)
{
    euleriana[++cnt] = nod;
    niveluri[cnt] = nivel;
    poz_noduri[nod] = cnt;
    for(auto x:adiacenta[nod])
    {
        parcurgere_euleriana(x,nivel+1);
        euleriana[++cnt] = nod;
        niveluri[cnt] = nivel;
    }
}
void init_rmq()
{
    for(int i = 1;i<=cnt;i++)
    {
        rmq_dp[i][0] = i;
    }
}
void rmq()
{
    int lungime;
    lungime = log2(cnt)+1;
    for(int j = 1;j<=lungime;j++)
    {
        for(int inceput = 1;inceput+(1<<(j-1))-1<=cnt;inceput++)
        {
            if(niveluri[rmq_dp[inceput][(j-1)]]<niveluri[rmq_dp[inceput+(1<<(j-1))][(j-1)]])
            {
                rmq_dp[inceput][j] = rmq_dp[inceput][(j-1)];
            }
            else
                {
                    rmq_dp[inceput][j] = rmq_dp[inceput+(1<<(j-1))][(j-1)];
                }
        }
    }
}
int aflare_rasp(int x,int y)
{
    int lungime = log2(y-x+1);
    int poz_min;
    if(niveluri[rmq_dp[x][lungime]]>niveluri[rmq_dp[y-(1<<lungime)+1][lungime]])
        return euleriana[rmq_dp[y-(1<<lungime)+1][lungime]];
    return euleriana[rmq_dp[x][lungime]];
}
void querys()
{

    for(int i = 1;i<=m;i++)
    {
        int x,y;
        f >> x >> y;
        int pozx = poz_noduri[x],pozy = poz_noduri[y];
        if(pozx>pozy)swap(pozx,pozy);

        g << aflare_rasp(pozx,pozy)<< endl;
    }
}
int main()
{
    citire();
    parcurgere_euleriana(1,0);
    init_rmq();
    rmq();
    querys();
}