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

ifstream fin("lca.in");
ofstream fout("lca.out");
int n, m;
vector <int> graph[100005];
int level[100005];
int ancestors[20][100005];

int logE;

int LCA(int a, int b)
{
    if (a == b)
    {
        return a;
    }
    for (int e = logE; e >= 0; e--)
    {
        if (ancestors[e][a] != ancestors[e][b])
        {
            a = ancestors[e][a];
            b = ancestors[e][b];
        }
    }
    return ancestors[0][a];
}

void Equalize(int &a, int &b)
{
    int e = logE;
    while (level[b] - level[a] > 0)
    {
        int dif = level[b] - level[a];
        if ((1 << e) <= dif)
        {
            b = ancestors[e][b];
        }
        e--;
    }
}

int DFS(int node, int lvl)
{
    level[node] = lvl;
    int currMax = lvl;
    for (int x : graph[node])
    {
        currMax = max(DFS(x, lvl + 1), currMax);
    }
    return currMax;
}



int main()
{
    fin >> n >> m;

    ancestors[0][1] = 1;
    for (int i = 1; i < n; i++)
    {
        int x;
        fin >> x;
        graph[x].push_back(i + 1);
        ancestors[0][i + 1] = x;
    }

    logE = (int)log2(DFS(1, 1));

    for (int e = 1; e <= logE; e++)
    {
        for (int i = 1; i <= n; i++)
        {
            ancestors[e][i] = ancestors[e - 1][ancestors[e - 1][i]];
        }
    }

    for (int i = 0; i < m; i++)
    {
        int a, b;
        fin >> a >> b;

        if (level[a] > level[b])
        {
            Equalize(b, a);
        }
        else
        {
            Equalize(a, b);
        }
        fout << LCA(a, b) << '\n';
    }
}