#include <bits/stdc++.h>


using namespace std;

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

const int Nmax = 1e5 + 5;

int euler[4 * Nmax], n, niv[Nmax], q, poz[Nmax], rmq[19][4 * Nmax], d, P[4 * Nmax];

vector < int > L[Nmax];

void DFS(int node, int N)
{
    ++d;
    euler[d] = node;
    niv[d] = N;
    poz[node] = d;
    for(auto it : L[node])
    {
        DFS(it, N + 1);
        ++d;
        euler[d] = node;
        niv[d] = N;
    }
}

int main()
{
    int x , y , k;
    fin >> n >> q;
    for(int i = 2 ; i <= n ; i++)
    {
        fin >> x;
        L[x].push_back(i);
    }
    DFS(1, 0);
    for(int i = 2 ; i <= d ; i++)
        P[i] = P[i / 2] + 1;
    for(int i = 1 ; i <= d ; i++)
        rmq[0][i] = i;
    for(int i = 1 ; (1 << i) <= d ; i++)
        for(int j = 1 ; j <= d ; j++)
        {
            rmq[i][j] = rmq[i - 1][j];
            if(niv[rmq[i - 1][j - (1 << (i - 1))]] < niv[rmq[i][j]])
                rmq[i][j] = rmq[i - 1][j - (1 << (i - 1))];
        }
    while(q--)
    {
        fin >> x >> y;
        x = poz[x];
        y = poz[y];
        if(x > y)
            swap(x , y);
        k = P[y - x + 1];
        if(niv[rmq[k][y]] <= niv[rmq[k][x + (1 << k) - 1]])
            x = rmq[k][y];
        else x = rmq[k][x + (1 << k) - 1];
        fout << euler[x] << "\n";
    }
    fin.close();
    fout.close();
}