#include <bits/stdc++.h>

using namespace std;

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

vector <int> h[100005];
int n, e[200005], niv[200005], lg[25], k , poz[200005], p , m;
int rmq[21][200005];
/**

e- retine nodurile in ordinea parcurgerii Euler
niv[i] = nivelul pe care se alfa nodul e[i]
poz[i] = o pozitie unde se gaseste nodul i in e[]

*/

void Euler (int k, int nivel)
{
    e[++p] = k;
    niv[p] = nivel;
    poz[k] = p;
    for (int i : h[k])
    {
        Euler(i, nivel + 1);
        e[++p] = k;
        niv[p] = nivel;
    }
}

void MakeRMQ ()
{
    lg[1] = 0;
    for (int i = 2; i <= p; i++)
        lg[i] = lg[i / 2] + 1;
    for(int i = 1; i <= p; i++)
        rmq[0][i] = i; /// e[i] este minim si se afla la poz i
    for (int i = 1; (1 << i) <= p; i++)
        for (int j = 1; j <= p - (1 << i) + 1; j++)
        {
            int len = (1 << (i - 1));
            rmq[i][j] = rmq[i - 1][j];
            if (niv[rmq[i - 1][j]] > niv[rmq[i - 1][j + len]])
                rmq[i][j] = rmq[i - 1][j + len];
        }
}

int main()
{
    fin >> n >> m;
    for (int i = 2; i <= n; i++)
    {
        int j;
        fin >> j;
        h[j].push_back(i);
    }
    Euler(1, 1);
    MakeRMQ();
    /// Interogari
    while (m--)
    {
        int x , y;
        fin >> x >> y;
        x = poz[x];
        y = poz[y];
        if (x > y)
            swap(x , y);
        int expo = lg[y - x + 1];
        int len = (1 << expo);
        int lca1 = rmq[expo][x];
        int lca2 = rmq[expo][y - len + 1];
        if (niv[lca1] > niv[lca2])
            fout << e[lca2] << "\n";
        else fout << e[lca1] << "\n";
    }
    return 0;
}