#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
#include <cmath>
#define int long long
#define NMAX  100002
#define LGMAX 20
using namespace std;
int n,x,y,m,cnt,ap[NMAX],e[2*NMAX];
vector<int> v[NMAX];
pair<int, int> rmq[LGMAX][2*NMAX];

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

void dfs(int nod, int niv){
    rmq[0][++cnt] = {nod, niv};
    ap[nod] = cnt;
    for(int fiu: v[nod]){
        dfs(fiu, niv+1);
        rmq[0][++cnt] = {nod, niv};
    }
}

int lca(int x, int y){
    int st = ap[x];
    int dr = ap[y];
    if(st > dr){
        swap(st, dr);
    }
    int len = dr-st+1;
    int log = e[len];
    pair<int, int> a = rmq[log][st];
    pair<int, int> b = rmq[log][dr-(1<<log)+1];
    if(a.second < b.second){
        return a.first;
    }
    return b.first;
}

signed main()
{
    fin >> n >> m;
    for(int i = 2; i <= n; i++){
        fin >> x;
        v[x].push_back(i);
    }
    dfs(1, 1);
    for(int i = 1; i < LGMAX; i++){
        for(int j = 1; j <= cnt; j++){
            rmq[i][j] = rmq[i-1][j];
            if(j+(1<<(i-1)) <= cnt){
                if(rmq[i][j].second > rmq[i-1][j+(1<<(i-1))].second){
                    rmq[i][j] = rmq[i-1][j+(1<<(i-1))];
                }
            }
        }
    }
    e[1] = 0;
    for(int i = 2; i <= cnt; i++){
        e[i] = 1+e[i/2];
    }
    while(m--){
        fin >> x >> y;
        fout << lca(x, y) << "\n";
    }
    return 0;
}