#include <fstream>
#include <vector>
#include <iostream>

using namespace std;

const int N = 1e5 + 5;
int n, q;
vector <int> et, level(2 * N), pos(N), L[N], exp(2 * N);
int rmq[20][2 * N];

void Euler_Tour(int, int);
void Build_RMQ();
int Query(int, int);

void Read ()
{
    ifstream fin ("lca.in");
    ofstream fout ("lca.out");
    fin >> n >> q;
    for (int i = 1, x; i < n; i++)
    {
        fin >> x;
        L[x].push_back(i + 1);
    }
    Euler_Tour(1, 1);
    Build_RMQ();
    for (int i = 1, x, y; i <= q; i++)
    {
        fin >> x >> y;
        fout << Query(x, y) << "\n";
    }
}

void Euler_Tour (int vertex, int currlevel)
{
    et.push_back(vertex);
    level[et.size()] = currlevel;
    if (!pos[vertex]) pos[vertex] = et.size();
    for (auto next : L[vertex])
    {
        Euler_Tour(next, currlevel + 1);
        et.push_back(vertex);
        level[et.size()] = currlevel;
    }
}

void Build_RMQ()
{
    for (int i = 2; i <= 2 * N; i++)
        exp[i] = exp[i / 2] + 1;
    for (int i = 1; i <= et.size(); i++)
        rmq[0][i] = i;
    for (int i = 1; i <= exp[et.size()]; i++)
        for (int j = 1; j <= et.size() - (1 << i) + 1; 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];
    return et[min(rmq[k][x], rmq[k][y - (1 << k) + 1]) - 1];
}

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