#include <fstream>
#include <vector>
#include <cmath>
using namespace std;

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

struct elem
{
    int val, etaj;
};

int n, q, rmq[20][400005], prima_ap[400005], x, y;
bool vizitat[100005];
vector<int> G[100005];
vector<elem> euler;

void buildRMQ()
{
    for (int i = 0; i < euler.size(); i++)
        rmq[0][i] = i;
    int logar = log2(n);
    for (int i = 1; i <= logar; i++)
    {
        int put = 1 << i;
        for (int j = 0; j + put < euler.size(); j++)
        {
            int st = rmq[i - 1][j];
            int dr = rmq[i - 1][j + (1 << (i - 1))];
            if (euler[st].etaj > euler[dr].etaj)
                rmq[i][j] = dr;
            else
                rmq[i][j] = st;
        }
    }
}

int query(int x, int y)
{
    if (prima_ap[x] > prima_ap[y])
        swap(x, y);
    int logar = log2(prima_ap[y] - prima_ap[x] + 1), sol;
    int st = rmq[logar][prima_ap[x]];
    int dr = rmq[logar][prima_ap[x] + (prima_ap[y] - prima_ap[x] + 1) - (1 << logar)];
    if (euler[st].etaj > euler[dr].etaj)
        sol = dr;
    else
        sol = st;
    return euler[sol].val;
}

void DFS(int nod, int etaj)
{
    vizitat[nod] = true;
    prima_ap[nod] = euler.size();
    euler.push_back({nod, etaj});
    for (int i = 0; i < G[nod].size(); i++)
    {
        int vecin = G[nod][i];
        if (vizitat[vecin] == false)
            DFS(vecin, etaj + 1);
        euler.push_back({nod, etaj});
    }
}

int main()
{
    fin >> n >> q;
    for (int i = 2; i <= n; i++)
    {
        int x;
        fin >> x;
        G[x].push_back(i);
    }
    DFS(1, 0);
    buildRMQ();
    for (int i = 0; i < q; i++)
    {
        fin >> x >> y;
        fout << query(x, y) << "\n";
    }
    return 0;
}