#include <fstream>
#include <vector>

using namespace std;

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

const int max_size = 1e5 + 1, rmax = 20;

int lin[2 * max_size], poz[max_size], rmq[rmax][4 * max_size], v[2 * max_size], timp, lg[max_size];
vector <int> mc[max_size];

void dfs (int nod, int nivel)
{
    timp++;
    lin[timp] = nod;
    poz[nod] = timp;
    v[timp] = nivel;
    for (auto f : mc[nod])
    {
        dfs(f, nivel + 1);
        lin[++timp] = nod;
        v[timp] = nivel;
    }
}

int main ()
{
    int n, q;
    in >> n >> q;
    for (int i = 2; i <= n; i++)
    {
        int x;
        in >> x;
        mc[x].push_back(i);
    }
    dfs(1, 1);
    for (int i = 1; i <= timp; i++)
    {
        rmq[0][i] = i;
        if (i > 1)
        {
            lg[i] = lg[i / 2] + 1;
        }
    }
    for (int e = 1; (1 << e) < timp; e++)
    {
        for (int i = 1; i <= timp - (1 << e); i++)
        {
            rmq[e][i] = rmq[e - 1][i];
            if (v[rmq[e - 1][i + (1 << (e - 1))]] < v[rmq[e][i]])
            {
                rmq[e][i] = rmq[e - 1][i + (1 << (e - 1))];
            }
        }
    }
    while (q--)
    {
        int x, y;
        in >> x >> y;
        x = poz[x];
        y = poz[y];
        if (x > y)
        {
            swap(x, y);
        }
        int diff = y - x + 1;
        int e = lg[diff], ans = rmq[e][x];
        if (v[rmq[e][x + diff - (1 << e)]] < v[ans])
        {
            ans = rmq[e][y - (1 << e) + 1];
        }
        out << lin[ans] << '\n';
    }
    in.close();
    out.close();
    return 0;
}