#include <bits/stdc++.h>
#define pb push_back
#define sz size()

using namespace std ;

const int NR = 100001 ;

ifstream f ("lca.in") ;
ofstream g ("lca.out") ;

vector < int > v [ NR ] ;

int level [ NR ], firstap [ NR ] , euler [ 2 * NR ] ;

int n , q , cnt ;

void input()
{
    f >> n >> q ;
    for ( int i = 2 ; i <= n ; ++ i )
    {
        int father ;
        f >> father ;
        v [ father ].pb( i ) ;
    }
    level [ 0 ] = -1 ;
}

void dfs ( int nod , int father )
{
    level [ nod ] = level [ father ] + 1 ;
    euler [ ++ cnt ] = nod ;
    firstap [ nod ] = cnt ;
    for ( size_t i = 0 ; i <  v[ nod ].sz ; ++ i )
    {
        dfs ( v [ nod ][ i ] , nod ) ;
        euler [ ++ cnt ] = nod ;
    }
}

int a[ 2 * NR ][ 20 ] ;
int lg [ 2 * NR ] ;

void rmq ()
{
    a [ 1 ][ 0 ] = euler [ 1 ] ;
    for ( int i = 2 ; i <= cnt ; ++ i )
    {
        lg [ i ] = lg [ i >> 1 ] + 1 ;
        a [ i ][ 0 ] = euler [ i ] ;
    }

    for( int j = 1 ; ( 1 << j ) <= cnt ; ++ j )
    for( int i = 1 ; i + ( 1 << j ) <= cnt + 1 ; ++ i )
    {
        a [ i ][ j ] = a [ i ][ j - 1 ] ;
        if ( level [ a [ i ][ j ] ] > level [ a [ i +  ( 1 << ( j - 1 ) )  ][ j - 1 ] ] )
        a[ i ][ j ] = a [ i + ( 1 << ( j - 1 ) ) ][ j - 1 ] ;
    }
}

void task ( int x , int y )
{
    int st = firstap [ x ] ;
    int dr = firstap [ y ] ;

    if ( st > dr )  swap ( st , dr ) ;

    int i = lg [ dr - st + 1 ] ;

    if ( level [ a [ st ][ i ] ] < level [ a [ dr - ( 1 << i ) + 1 ][ i ] ] )
        g << a [ st ][ i ] << "\n" ;
    else
        g << a [ dr - ( 1 << i ) + 1 ][ i ] << "\n" ;
}

void solve_tasks ()
{
    while ( q -- )
    {
        int x , y ;
        f >> x >> y ;
        task ( x , y ) ;
    }
}


int main ()
{
    input() ;
    dfs ( 1 , 0 ) ;
    rmq() ;
    solve_tasks() ;
    return 0 ;
}