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

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

int n, m;
int a, b, cnt;
vector<int> log2, poz, niv, E;
vector<vector<int>> g, answ;

void Df(int nod, int nv);
void Read();
void Query();
void RMQ();

int main()
{
    Read();
    Df(1, 1);
    RMQ();
    Query();
    is.close();
    os.close();
    return 0;
}

void RMQ()
{
    int N = 2 * n - 1;
    for ( int i = 1; i <= N; ++i )
        answ[i][0] = i;
    for ( int j = 1; ( 1 << j ) <= N; ++j )
        for ( int i = 1; i + ( 1 << j ) - 1 <= N; ++i )
            if ( niv[answ[i][j - 1]] < niv[answ[i + (1 << (j - 1))][j - 1]] )
                answ[i][j] = answ[i][j - 1];
            else
                answ[i][j] = answ[i + (1 << (j - 1))][j - 1];
}

void Df(int nod, int nv)
{
    E[++cnt] = nod;
    niv[cnt] = nv;
    poz[nod] = cnt;
    for ( const auto& nodv : g[nod] )
    {
        Df(nodv, nv + 1);
        E[++cnt] = nod;
        niv[cnt] = nv;
    }
}

void Read()
{
    int n1;
    is >> n >> m;
    g = vector<vector<int>>(n + 1);
    E = vector<int>(2 * n);
    niv = vector<int>(2 * n);
    poz = vector<int>(n + 1);
    log2 = vector<int>(2 * n);
    answ = vector<vector<int>>(2 * n, vector<int>(20));
    for ( int i = 2; i <= n; ++i )
    {
        is >> n1;
        g[n1].push_back(i);
    }
    for ( int i = 2; i < 2 * n; ++i )
        log2[i] = log2[i / 2] + 1;
}

void Query()
{
    int a, b, x, y, z;
    while ( m-- )
    {
        is >> a >> b;
        x = poz[a];
        y = poz[b];
        if ( x > y )
            swap(x, y);
        z = log2[y - x + 1];
        if ( niv[answ[x][z]] < niv[answ[y - (1 << z) + 1][z]] )
            os << E[answ[x][z]] << "\n";
        else
            os << E[answ[y - (1 << z) + 1][z]] << "\n";
    }
}