#include <fstream>
#include <iostream>
#include <vector>
#define infinit 999999999

using namespace std;

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

vector<vector <int>> graph;
vector<pair<int, int>> queries;
vector<int> answers;
int parcurgere[4000010], nivel[4000010], prima[1000010], viz[1000010] = {0};
int dp[4000010][22] , log[4000010];
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 < graph[nod].size(); i++)
    {
        parcurgere_euleriana(graph[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]]);
    }
}

void lca(const std::vector<std::vector<int>>& graph, const std::vector< std::pair<int, int> >& queries) {
    // TODO
    //std::vector<std::vector<int> > tati(graph.size());
  //  creare_tati(1, graph, 0, tati);
    parcurgere_euleriana(1, 0);
    std::vector<int> answers(queries.size(), 0);
    for(int i = 1; i <= k; i++)
        dp[i][0] = minim_corect(nivel[i], nivel[i+1], i, i+1);
    dp[k][0] = parcurgere[k];
    for(int 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 < queries.size(); i++)
    {
        if(prima[queries[i].first] < prima[queries[i].second])
            answers[i] = parcurgere[interogare(prima[queries[i].first], prima[queries[i].second])];
        else
            answers[i] = parcurgere[interogare(prima[queries[i].second], prima[queries[i].first])] ;
    }
    for(int i = 0; i < queries.size(); i++){
      g << answers[i] << '\n';
    }
    //return answers;
}


int main(){
    int n, m;
    f >> n >> m;
    graph.resize(n+1);
    queries.resize(m);
    answers.resize(m);
    for(int i = 2; i <= n; i++){
      int x, y;
      //f >> x >> y;
      f >> x;
      graph[x].push_back(i);
      //graph[y].push_back(x);
    //  graph[x].push_back(y);
    }
    for(int i = 0; i < m; i++){
      int x, y;
      f >> x >> y;

      queries[i] = make_pair(x, y);
    }
    lca(graph, queries);

    return 0;

}