#include <fstream>
#include <vector>
#include <cmath>
#define NMAX 100005
#define LMAX 20

using namespace std;

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

int i, n, m, x, euler[4 * NMAX], rmq[LMAX][4 * NMAX], cnt = 0, lvl[4 * NMAX], pos[NMAX], j;
bool visited[NMAX];

vector < int > v[NMAX];

void DFS(int node, int level)
{
    visited[node] = 1;
    euler[++ cnt] = node;
    lvl[cnt] = level;

    if (pos[node] == 0)
        pos[node] = cnt;

    for (vector < int > :: iterator it = v[node].begin(); it != v[node].end(); ++ it)
        if (!visited[*it])
        {
            DFS(*it, level + 1);
            euler[++ cnt] = node;
            lvl[cnt] = level;
        }
}

int main()
{
    f >> n >> m;

    for (i = 2; i <= n; ++ i)
    {
        f >> x;
        v[i].push_back(x);
        v[x].push_back(i);
    }

    DFS(1, 1);

  /*  for (i = 1; i <= cnt; ++ i)
        g << euler[i] << " ";
    g << '\n';

    for (i = 1; i <= cnt; ++ i)
        g << lvl[i] << " ";*/

    for (i = 1; i <= cnt; ++ i)
        rmq[0][i] = i;

    for (j = 1; (1 << j) <= cnt; ++ j)
        for (i = 1; i + (1 << j) - 1 <= cnt; ++ i)
            if (lvl[rmq[j - 1][i]] < lvl[rmq[j - 1][i + (1 << (j - 1))]])
                rmq[j][i] = rmq[j - 1][i];
            else
                rmq[j][i] = rmq[j - 1][i + (1 << (j - 1))];

    for (i = 1; i <= m; ++ i)
    {
        int st, dr;

        f >> st >> dr;

        st = pos[st];
        dr = pos[dr];

        if (st > dr)
            swap(st, dr);

        int l = log2(dr - st + 1);

        if (lvl[rmq[l][st]] < lvl[rmq[l][dr - (1 << l) + 1]])
            g << euler[rmq[l][st]] << '\n';
        else
            g << euler[rmq[l][dr - (1 << l) + 1]] << '\n';
    }

    return 0;
}