#include <bits/stdc++.h>

using namespace std;

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

int n, m, k, e[2000005], niv[2000005], poz[2000005], p2[2000005];
int rmq[22][2000005]; /// rmq[i][j] min pe intervalul [j..j + 2 ^ i - 1]
/// /// indicele unde niv este minim
vector <int> a[100005];

void Dfs(int x, int lvl)
{
    e[++k] = x;
    niv[k] = lvl;
    poz[x] = k;
    for (auto w : a[x])
    {
        Dfs(w, lvl + 1);
        e[++k] = x;
        niv[k] = lvl;
    }
}

int main()
{
    int i, j, x, lg, sol1, sol2;
    fin >> n >> m;
    for (i = 2; i <= n; i++)
    {
        fin >> x;
        a[x].push_back(i);
    }

    Dfs(1, 0);

    p2[1] = 0;
    for (i = 2; i <= k; i++)
        p2[i] = p2[i / 2] + 1;


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

    for (i = 1; i <= p2[k]; i++)
        for (j = 1; j <= k - (1 << i) + 1; j++)
        {
            rmq[i][j] = rmq[i - 1][j];
            if (niv[ rmq[i - 1][j] ] > niv [ rmq[i - 1][j + (1 << (i - 1)) ] ])
                rmq[i][j] = rmq[i - 1][j + (1 << (i - 1)) ];
        }

    while (m--)
    {
        fin >> i >> j;
        i = poz[i];
        j = poz[j];
        lg = p2[j - i + 1];
        sol1 = rmq[lg][i];
        sol2 = rmq[lg][j - (1 << lg) + 1];
        if (niv[sol1] < niv[sol2])
            fout << e[sol1] << "\n";
        else fout << e[sol2] << "\n";
    }



    return 0;
}