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

using namespace std;

const int N = 1e5 + 5;

vector <int> eultour, level(N), pos(N), exp (2 * N), L[N];
int rmq[20][2 * N], n;

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

void Build_RMQ()
{
    int n = eultour.size();
    for (int i = 2; i <= n; i++)
        exp[i] = exp[i >> 1] + 1;
    for (int i = 1; i <= n; i++)
        rmq[0][i] = i;
    for (int i = 1; i <= exp[n]; i++)
        for (int j = 1; j <= n - (1 << i) + 1; j++)
        {
            int x = rmq[i - 1][j];
            int y = rmq[i - 1][j + (1 << (i - 1))];
            if (level[eultour[x - 1]] < level[eultour[y - 1]]) rmq[i][j] = x;
            else rmq[i][j] = y;
        }
}

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];
    int min1 = rmq[k][x];
    int min2 = rmq[k][y - (1 << k) + 1];
    if (level[eultour[min1 - 1]] < level[eultour[min2 - 1]]) return eultour[min1 - 1];
    return eultour[min2 - 1];
}

void Read ()
{
    ifstream fin ("lca.in");
    int q;
    fin >> n >> q;
    for (int i = 1, x; i < n; i++)
    {
        fin >> x;
        L[x].push_back(i + 1);
    }
    Euler_Tour(1, 0);
    Build_RMQ();
    ofstream fout ("lca.out");
    while (q--)
    {
        int x, y;
        fin >> x >> y;
        fout << Query(x, y) << "\n";
    }
    fout.close();
}

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