#include <bits/stdc++.h>

using namespace std;

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

int n, e[200005], niv[200005], p, poz[100005];
vector <int> h[100005];
int rmq[25][1000005], p2[100005];
/**
e = parcurgerea Euler a nodurilor
niv[i] = niv nodului e[i], i = 1...p
poz[i] = o poz unde se gaseste nodul i in e[], i = 1...n
p2[i] = lung putere a lui 2 max a unui interval cu lung i
rmq[i][j] = poz min din intervalul [j, j + 2^i - 1], i = 0...k, 2^k <= p
*/

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;
    }
}

int main()
{

    int q, i, j;
    fin >> n >> q;
    for (i = 2; i <= n; i++)
    {
        fin >> j;
        h[j].push_back(i);
    }
    Euler(1, 1);
    ///-------------------RMQ (Range Minimum Query)
    p2[1] = 0;
    for (i = 2; i <= p; i++)
        p2[i] = 1 + p2[i / 2];
    for (i = 1; i <= p; i++)
        rmq[0][i] = i;
    for (i = 1; (1 << i) <= p; i++)
        for (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];
        }
    ///------------------interogari
    while (q--)
    {
        fin >> i >> j;
        i = poz[i];
        j = poz[j];
        if (i > j) swap(i, j);
        int expo = p2[j - i + 1];
        int len = 1 << expo;
        int sol1 = rmq[expo][i];
        int sol2 = rmq[expo][j - len + 1];
        if (niv[sol1] > niv[sol2]) fout << e[sol2] << "\n";
        else fout << e[sol1] << "\n";
    }
    return 0;
}