#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

const int N = 100001, L = 18;
int log[L], r[L][2*N], e[2*N], ne, nivel[N], poz[N];

vector <int> fii[N];

void dfs ( int x )
{
    e[++ne] = x;
    poz[x] = ne;
    for ( auto y : fii[x])
    {
        nivel[y] = 1 + nivel[x];
        dfs(y);
        e[++ne] = x;
    }
}

int main()
{
    int n, m;
    fin >> n >> m;
    for ( int i = 2; i <= n; i++ )
    {
        int x;
        fin >> x;
        fii[x].push_back (i);
    }
    dfs (1);
    for ( int i = 2; i <= ne; i++ )
    {
        log[i] = log[i/2] + 1;
    }
    for ( int j = 1; j <= ne; j ++ )
    {
        r[0][j] = e[j];
    }
    for ( int i = 1; i <= log[ne]; i++ )
    {
        for ( int j = 1 << i; j <= ne; j++ )
        {
            int st, dr;
            st = r[i-1][j - ( 1 << ( i-1 ) )];
            dr = r[i-1][j];
            if ( nivel [st] <= nivel[dr] )
            {
                r[i][j] = st;
            }
            else
            {
                r[i][j] = dr;
            }
        }
    }
    while ( m != 0 )
    {
        int x, y;
        m--;
        fin >> x >> y;
        if ( poz[x] > poz[y] )
        {
            x += y;
            y = x - y;
            x = x - y;
        }
        int lung = poz[y] - poz[x] + 1;
        int l = log[lung];
        if ( nivel[r[l][poz[y]]] < nivel [r[l][poz[x] + (1 << l )]])
        fout << r[l][poz[y]] << "\n";
        else
        fout << r[l][poz[x] + (1 <<l)] << "\n";
    }
    return 0;
}