#include <bits/stdc++.h>

using namespace std;

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

const int DIM = 100005;
int n, q;
int level[DIM], stramos[DIM][17];

int up(int nod, int dist){
    int p2 = 0;
    while(dist != 0){
        if(dist&1)
            nod = stramos[nod][p2];

        p2++;
        dist >>= 1;
    }
    return nod;
}

int main (){
    fin >> n >> q;
    stramos[1][0] = level[1] = 1;
    for(int i = 2; i <= n; i++){
        fin>>stramos[i][0];
        level[i] = level[ stramos[i][0] ] + 1;
    }
    /*
    for(int i=1; i<=n; i++)
        cout<<level[i]<<" ";
    cout<<"\n";
    */
    for(int j = 1; (1 << j) <= n; j++)
        for(int i = 1; i <= n; i++)
            stramos[i][j] = stramos[ stramos[i][j-1] ][j-1];

    int x, sx, y, sy, st, md, dr, sol;
    while(q--){
        fin >> x >> y;


        if(level[x] < level[y]) ///x mai sus decat y, atunci swap
            swap(x, y);

        //cout<<"("<<x<<", "<<y<<") -> ";
        x = up(x, level[x] - level[y]); ///ac nivel
        //cout<<"("<<x<<", "<<y<<")\n";


        st = 0;
        dr = level[y]-1;
        while(st <= dr){
            md = (dr - st) / 2 + st;

            sx = up(x, md);
            sy = up(y, md);

            if(sx == sy){
                sol = sx;
                dr = md-1;
            }else
                st = md+1;
        }
        fout << sol << "\n";
    }
    return 0;
}