#include <fstream>
#include <iostream>
#include <vector>

#define NMAX 100005
#define LOG 20
using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

int n, m;
vector<int> G[NMAX];
vector<int> v;
vector<int>depth;
int nr;
int dp[NMAX*100][LOG];
int d[NMAX];
int first[NMAX],uz[NMAX];
void citire()
{
  fin >> n >> m;
  int a;
  for (int i = 1; i < n; i++)
  {
    fin>>a;
    G[a].push_back(i + 1);
  }
}
///parcurgere euler
void dfs(int nod, int tata)
{
    v.push_back(nod);
    d[nod]=d[tata]+1;
    depth.push_back(d[nod]);
    int poz=v.size()-1;
    if(!uz[nod])
    {
        uz[nod]=1;
        first[nod]=poz;
    }
    for(int i=0;i<G[nod].size();i++)
    {
       dfs(G[nod][i],nod);
       v.push_back(nod);
       depth.push_back(d[nod]);
    }

}
int rmq(int x, int y)
{
    if(y<x) swap(x,y);
    int k=y-x+1,i=0;
    while((1<<i)<=k) i++;
    k=i-1;
    if(depth[dp[x][k]]<depth[dp[y-(1<<k)+1][k]])
    return v[dp[x][k]];
    return v[dp[y-(1<<k)+1][k]];
}
int main()
{
    citire();
    dfs(1, 0);
    ///RMQ
    nr=depth.size()-1;
    /*for(int i=0;i<=nr;i++) fout<<v[i]<<" ";
    fout<<endl;
    for(int i=0;i<=nr;i++) fout<<depth[i]<<" ";
    fout<<endl;*/
    for(int i=0;i<=nr;i++) dp[i][0]=i;

    for(int j=1;(1<<j)<=nr;j++)
        for(int i=0;i<=nr -(1<<j)+1;i++)
        {
            if(depth[dp[i][j-1]]<=depth[dp[i+(1<<(j-1))][j-1]])
                dp[i][j]=dp[i][j-1];
            else
                dp[i][j]=dp[i+(1<<(j-1))][j-1];
        }
    for(int i=1;i<=m;i++)
    {
        int a,b;
        fin>>a>>b;
        fout<<rmq(first[a],first[b])<<endl;
    }
    return 0;
}