#include <iostream>
#include <fstream>
#include <vector>
#define infinit 999999999
using namespace std;

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

int parcurgere[400010], nivel[400010], prima[100010], viz[100010];
int dp[400010][22], log[400010];
vector < vector<int>> vecini;
int k = 1;
int parcurgere_euleriana(int nod, int nivel_actual)
{
    parcurgere[k] = nod;
    nivel[k] = nivel_actual;
    if(viz[nod] == 0)
    {
        prima[nod] = k;
        viz[nod] = 1;
    }
    k++;
    for(int i = 0; i < vecini[nod].size(); i++)
    {
        parcurgere_euleriana(vecini[nod][i], nivel_actual + 1);
        parcurgere[k] = nod;
        nivel[k] = nivel_actual;
        k++;
    }
    return 0;
}

int minim(int a, int b)
{
  if(a == infinit)
    return b;
  if(b == infinit)
    return a;
  if(nivel[a] < nivel[b])
        return a;
  return b;
}

int minim_corect(int a, int b, int x, int y)
{

    if(a < b)
        return x;
    return y;
}

int interogare(int x, int y)
{
    if(x == y)
      return x;
    else
    {
      int dif;
      dif = y - x ;
      return minim(dp[x][log[dif]], dp[y-(1<<log[dif])][log[dif]]);
    }
}

int main()
{
    int n, m, x, i, j, y;
    f >> n >> m;
    vecini.resize(n+1);
    for(int i = 2; i <= n ; i++)
    {
        f >> x;
        vecini[x].push_back(i);
    }
    parcurgere_euleriana(1, 0);
    for(i = 1; i <= k; i++)
        dp[i][0] = minim_corect(nivel[i], nivel[i+1], i, i+1);
    dp[k][0] = parcurgere[k];
    for(i = 2; i <= k; i++)
        log[i] = log[i/2] + 1;
    for(int j = 1; j <= log[k]; j++)
        for(int i = 1;(i + (1 << (j-1))) <= k ; i++)
            dp[i][j] = minim(dp[i][j-1], dp[i  + (1 << (j-1))][j-1]);
    for(int i = 0; i < m; i++)
    {
        f >> x >> y;
        if(prima[x] < prima[y])
            g << parcurgere[interogare(prima[x], prima[y])] << '\n';
        else
            g << parcurgere[interogare(prima[y], prima[x])] << '\n';

    }
    return 0;
}