#include <bits/stdc++.h>
using namespace std;

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

int n, Q, m;
int e[200005], P[200005], nivel[200005], expo[200005], rmq[20][200005];
vector<int> L[100005];

void Euler(int k, int level)
{
    e[++m] = k;
    P[k] = m;
    nivel[m] = level;
    for (int i : L[k])
    {
        Euler(i, level + 1);
        e[++m] = k;
        nivel[m] = level;
    }
}

void MakeRMQ()
{
    int i, j, L, A, B;
    expo[1] = 0;
    for (i = 2; i <= m; i++)
        expo[i] = expo[i / 2] + 1;

    for (i = 1; i <= m; i++)
        rmq[0][i] = i;
    for (i = 1; i <= expo[m]; i++)
    {
        L = (1 << i);
        for (j = 1; j <= m - L + 1; j++)
        {
            A = rmq[i - 1][j];
            B = rmq[i - 1][j + L / 2];

            if (nivel[A] <= nivel[B])
                rmq[i][j] = A;
            else
                rmq[i][j] = B;
        }
    }
}

void Query(int A, int B)
{
    int E, L, Lca;

    A = P[A]; B = P[B];
    if (A > B)
        swap(A, B);
    E = expo[B - A + 1];
    L = (1 << E);

    A = rmq[E][A];
    B = rmq[E][B - L + 1];

    if (nivel[A] <= nivel[B])
        Lca = A;
    else
        Lca = B;
    fout << e[Lca] << "\n";
}
int main()
{
    int i, j;
    fin >> n >> Q;
    for (i = 2; i <= n; i++)
    {
        fin >> j;
        L[j].push_back(i);
    }
    Euler(1, 1);
    MakeRMQ();
    while (Q--)
    {
        fin >> i >> j;
        Query(i, j);
    }
    return 0;
}