//euler+rmq

#include <bits/stdc++.h>

using namespace std;

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

const int nmax = 2e5 + 5;

vector <int> g[nmax];
int n, m, k, euler[nmax], lvl[nmax], poz[nmax], lg[nmax], rmq[20][nmax];

void build (int nod, int h)
{
    euler[++k] = nod;
    lvl[k] = h;
    poz[nod] = k;
    for (auto it : g[nod])
    {
        build (it, h + 1);
        euler[++k] = nod;
        lvl[k] = h;
    }
}

void init ()
{
    for (int i = 2; i <= k; i++)
        lg[i] = lg[i / 2] + 1;
    for (int i = 1; i <= k; i++)
        rmq[0][i] = i;
    for (int i = 1; i <= lg[k]; i++)
    {
        for (int j = 1; j <= k - (1 << i) + 1; j++)
        {
            int l = 1 << (i - 1);
            rmq[i][j] = rmq[i - 1][j];
            if (lvl[rmq[i - 1][j + l]] < lvl[rmq[i][j]]) rmq[i][j] = rmq[i - 1][j + l];
        }
    }
}

int query (int x, int y)
{
    int k = lg[y - x];
    int sol = rmq[k][x];
    if (lvl[rmq[k][y - (1 << k) + 1]] < lvl[sol])
        sol = rmq[k][y - (1 << k) + 1];
    return sol;
}

int lca (int x, int y)
{
    x = poz[x];
    y = poz[y];
    if (x > y)
        swap (x, y);
    return euler[query (x, y)];
}

int main ()
{
    fin >> n >> m;
    for (int i = 2; i <= n; i++)
    {
        int x;
        fin >> x;
        g[x].push_back (i);
    }
    build (1, 1);
    init ();
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        fout << lca (x, y) << '\n';
    }
    return 0;
}