#include <bits/stdc++.h>

#define K_MAX 17
using namespace std;

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

int N, M;

vector<int>father,euler,_first, level, Log2;
vector<vector<int>>rmq;

void DFS(int root, int previous, int currentHeight)
{
    level[root] = level[previous] + 1;
    euler[++euler[0]] = root;
    if (!_first[root])
        _first[root] = euler[0];

    for (int i = 1; i <= N; ++i)
        if (father[i] == root)
        {
            DFS(i, root, currentHeight + 1);
            euler[++euler[0]] = root;
        }
}

void computeRMQ()
{
    rmq[0][1] = euler[1];

    for (int i = 2; i <= euler[0]; ++i)
    {
        Log2[i] = Log2[i >> 1] + 1;
        rmq[0][i] = euler[i];
    }

    for (int i = 1; (1 << i) <= euler[0]; ++i)
        for (int j = 1; j <= euler[0] - (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 LCA(int node1, int node2)
{
    node1 = _first[node1];
    node2 = _first[node2];

    if (node1 > node2)
        swap(node1, node2);


    int k = Log2[node2 - node1];
    if (level[rmq[k][node1]] < level[rmq[k][node2 - (1 << k) + 1]])
        return rmq[k][node1];

    return rmq[k][node2 - (1 << k) + 1];
}

int main()
{
    fin >> N >> M;
    father.resize(N + 1, 0);
    euler.resize(N << 1, 0);
    _first.resize(N + 1, 0);
    rmq.resize(K_MAX + 1, vector<int>(N << 1, 0));
    Log2.resize(N << 1, 0);
    level.resize(N + 1, 0);

    for (int i = 2; i <= N; ++i)
        fin >> father[i];

    DFS(1, 0, 0);
    computeRMQ();

    for(int p, q; M; --M)
    {
        fin >> p >> q;
        fout << LCA(p, q) << "\n";
    }
    return 0;
}