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

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

int e[400005], expo[400005], niv[400005], p[400005], n, m, len;
int rmq[20][400001];
vector <int> g[100005];

void DFS(int k, int level)
{
    e[++len] = k;
    niv[len] = level;
    p[k] = len;
    for (int i : g[k])
    {
        DFS(i, level + 1);
        e[++len] = k;
        niv[len] = level;
    }
}

int main()
{
    int i, j, exp, L, x;
    fin >> n >> m;
    for (i = 2; i <= n; i++)
    {
        fin >> x;
        g[x].push_back(i);
    }

    DFS(1, 0);
    for (i = 2; i <= len; i++)
        expo[i] = 1 + expo[i / 2];
    for (i = 1; i <= len; i++)
        rmq[0][i] = i;
    for (i = 1; i <= expo[len]; i++)
    {
        L = (1 << i);
        for (j = 1; j <= len - L + 1; j++)
            if (niv[rmq[i - 1][j]] < niv[rmq[i - 1][j + L / 2]])
                rmq[i][j] = rmq[i - 1][j];
            else
                rmq[i][j] = rmq[i - 1][j + L / 2];
    }

    while (m--)
    {
        fin >> i >> j;
        i = p[i];
        j = p[j];
        if (i > j)
            swap(i, j);
        exp = expo[j - i + 1];
        L = (1 << exp);
        if (niv[rmq[exp][i]] < niv[rmq[exp][j - L + 1]])
            fout << e[rmq[exp][i]] << "\n";
        else
            fout << e[rmq[exp][j - L + 1]] << "\n";
    }
    return 0;
}