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

ifstream is("lca.in");
ofstream os("lca.out");

using VI = vector<int>;
using VVI = vector<VI>;

int n, m, N;
VI e, nv, poz, log2;
VVI g, r;

void read();
void euler(int nod, int niv);
void rmq();
void query();

int main()
{
    read();
    e.push_back(0);
    nv.push_back(0);
    poz = VI(2 * n + 1);
    euler(1, 1);
    rmq();
    query();
    is.close();
    os.close();
    return 0;
}

void query()
{
    int x, y, v;
    while ( m-- )
    {
        is >> x >> y;
        x = poz[x];
        y = poz[y];
        if ( x > y )
            swap(x, y);
        v = log2[y - x + 1];
        if ( nv[r[x][v]] < nv[r[y - (1 << v) + 1][v]] )
            os << e[r[x][v]] << "\n";
        else
            os << e[r[y - (1 << v) + 1][v]] << "\n";
    }
}

void euler(int nod, int niv)
{
    poz[nod] = e.size();
    e.push_back(nod);
    nv.push_back(niv);
    for ( const auto &nodv : g[nod] )
        if ( !poz[nodv] )
        {
            euler(nodv, niv + 1);
            e.push_back(nod);
            nv.push_back(niv);
        }
}

void rmq()
{
    N = 2 * n - 1;
    log2 = VI(N + 1);
    for ( int i = 2; i <= N; ++i )
        log2[i] = log2[i / 2] + 1;
    r = VVI(N + 1, VI(20));
    for ( int i = 1; i <= N; ++i )
        r[i][0] = i;
    for ( int j = 1; ( 1 << j ) <= N; ++j )
        for ( int i = 1; i + ( 1 << j ) - 1 <= N; ++i )
            if ( nv[r[i][j - 1]] < nv[r[i + ( 1 << (j - 1) )][j - 1]] )
                r[i][j] = r[i][j - 1];
            else
                r[i][j] = r[i + ( 1 << (j - 1) )][j - 1];
}

void read()
{
    is >> n >> m;
    g = VVI(n + 1);
    int x;
    for ( int i = 2; i <= n; ++i )
    {
        is >> x;
        g[x].push_back(i);
    }
}