#include <fstream>
#include <vector>
#include <iostream>
#include <algorithm>
#include <set>

using namespace std;

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

const int N = 1e5 + 2;

vector <int> L[N], euler, level, pos;
int n, q, rmq[18][2 * N], exp[2 * N];

void EulerTour(int nod, int currlevel)
{
    euler.push_back(nod);
    level.push_back(currlevel);
    if (!pos[nod]) pos[nod] = euler.size() - 1;
    for (auto next : L[nod])
    {
        EulerTour(next, currlevel + 1);
        euler.push_back(nod);
        level.push_back(currlevel);
    }
}

void Build_RMQ()
{
    exp[1] = 0;
    for (int i = 2; i < euler.size(); i++)
        exp[i] = exp[i / 2] + 1;
    for (int i = 1; i < euler.size(); i++)
        rmq[0][i] = i;
    for (int i = 1; i <= exp[euler.size() - 1]; i++)
        for (int j = 1; j <= euler.size() - (1 << i); j++)
            if (level[rmq[i - 1][j]] < level[rmq[i - 1][j + (1 << (i - 1))]])
                rmq[i][j] = rmq[i - 1][j];
            else rmq[i][j] = rmq[i - 1][j + (1 << (i - 1))];
}

int Query (int a, int b)
{
    int x = pos[a];
    int y = pos[b];
    if (x > y) swap(x, y);
    int k = exp[y - x + 1];
    if (level[rmq[k][x]] < level[rmq[k][y - (1 << k) + 1]])
        return euler[rmq[k][x]];
    return euler[rmq[k][y - (1 << k) + 1]];
}

void Read()
{
    fin >> n >> q;
    for (int i = 2; i <= n; i++)
    {
        int x;
        fin >> x;
        L[x].push_back(i);
    }
    pos.resize(n + 1, 0);
    euler.push_back(2e9);
    level.push_back(2e9);
    EulerTour(1, 1);
    Build_RMQ();
}

void Solve()
{
    for (int i = 1; i <= q; i++)
    {
        int x, y;
        fin >> x >> y;
        fout << Query(x, y) << '\n';
    }
}

int main()
{
    Read();
    Solve();
    return 0;
}