#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1e5 + 1, LOG = 17;

vector <int> sons[NMAX];
int anc[NMAX][LOG + 1];
int level[NMAX];

void dfs ( int nod, int lvl )
{
    level[nod] = lvl + 1;
    for ( int i = 1; i < LOG && anc[nod][i - 1]; i ++ )
        anc[nod][i] = anc[anc[nod][i - 1]][i - 1];
    for ( auto it : sons[nod] )
        dfs ( it, lvl + 1 );
}

int ancestor ( int nod, int exp )
{
    for ( int i = LOG; i >= 0; i -- )
    {
        if ( ( 1 << i ) <= exp )
        {
            exp -= ( 1 << i );
            nod = anc[nod][i];
        }
    }
    return nod;
}

void balance_level ( int &a, int &b )
{
    if ( level[a] == level[b] )
        return;
    if ( level[a] < level[b] )
        swap ( a, b );
    a = ancestor ( a, level[a] - level[b] );
}

int lca ( int a, int b )
{
    balance_level ( a, b );
    if ( a == b )
        return a;
    for ( int i = LOG; i >= 0; i -- )
    {
        if ( anc[a][i] != anc[b][i] )
            return lca ( anc[a][i], anc[b][i] );
    }
    if ( anc[a][0] == anc[b][0] )
        return anc[a][0];
    else return 0;
}

int main()
{
    int n, q;
    f >> n >> q;
    for ( int i = 2; i <= n; i ++ )
    {
        int x;
        f >> x;
        anc[i][0] = x;
        sons[x].push_back(i);
    }
    dfs ( 1, 0 );
    while ( q -- )
    {
        int a, b;
        f >> a >> b;
        g << lca( a, b ) << '\n';
    }
    return 0;
}