#include <bits/stdc++.h>
#include <fstream>
#define NMAX 100005
using namespace std;

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

int n, m, r, nivel;

vector<int> v[NMAX];
int v4[NMAX];
vector<int> v2;
vector<int> v3;
pair<int, int> z[20][2*NMAX];

void dfs(int nod)
{
    nivel++;
    for(auto i:v[nod])
    {
        v2.push_back(nod);
        v3.push_back(nivel);
        dfs(i);
    }
    v3.push_back(nivel);
    v2.push_back(nod);
    nivel--;
}


int main()
{
    fin>>n>>m;
    int x;
    for(int i=2; i<=n; i++)
    {
        fin>>x;
        v[x].push_back(i);
    }
    dfs(1);

    for(int i=0; i<v3.size(); i++)
    {
        z[0][i].first = v3[i];
        z[0][i].second = i;
       // cout<<z[0][i].first<<' ';
    }

    for(int j=1; (1<<j)<=v3.size(); j++)
    {
        for(int i=0; i+(1<<(j-1))<v3.size(); i++)
        {
            if(z[j-1][i].first<=z[j-1][i+(1<<(j-1))].first){
                z[j][i].first = z[j-1][i].first;
                z[j][i].second = z[j-1][i].second;
            }
            else
            {
                z[j][i].first = z[j-1][i+(1<<(j-1))].first;
                z[j][i].second = z[j-1][i+(1<<(j-1))].second;
            }
        }
    }

    int y;
    for(int i=0; i<v2.size(); i++)
    {
        v4[v2[i]] = i;
    }

    int j = 0;

    for(int i=0; i<m; i++)
    {
        fin>>x>>y;
        x = v4[x];
        y = v4[y];
        j=0;
        while(x+(1<<j)-1<=y)
            j++;
        j--;
        if(z[j][x]<=z[j][y-(1<<j)+1])
            fout<<v2[z[j][x].second]<<'\n';
        else
            fout<<v2[z[j][y-(1<<j)+1].second]<<'\n';

    }
    return 0;
}