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

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

vector < vector<int>> v, lant;

int tati[100010], nivel[100010], boss[100010], k, care[100010], dp[30][200010];

int DFS(int nod, int nivel_actual)
{
    nivel[nod] = nivel_actual;
    int ok = 0;
    for(int i = 0 ; i < v[nod].size(); i++)
    {
        ok = 1;
        DFS(v[nod][i], nivel_actual + 1);
    }
    if(ok == 0)
    {
        lant[k].push_back(nod);
        care[nod] = k;
        k++;
    }
    else
    {
        int pe_care, maxim = 0;
        for(int i = 0; i < v[nod].size(); i++)
        {
            if(lant[care[v[nod][i]]].size() > maxim)
            {
                maxim = lant[care[v[nod][i]]].size();
                pe_care = care[v[nod][i]];
            }
        }
        lant[pe_care].push_back(nod);
        care[nod] = pe_care;
        for(int i = 0; i < v[nod].size(); i++)
        {
            if(care[v[nod][i]] != pe_care)
                boss[care[v[nod][i]]] = nod;
        }

    }
    return 0;
}

int creez_dinamica(int n)
{
    for(int j = 1 ; j < 15; j++)
        for(int i = 1; i <= n; i++)
            dp[j][i] = dp[j - 1][dp[j - 1][i]];
}

int query(int x, int y)
{
    if(care[x] == care[y])
    {
        if(nivel[x] > nivel[y])
            return y;
        else
            return x;
    }
    else
    {
        for(int bit = 15; bit >= 0; bit--)
        {
            if(bit != 0)
            {
                if(care[dp[bit][x]] == care[dp[bit][y]] && care[dp[bit - 1][x]] != care[dp[bit - 1][y]])
                        return query(dp[bit - 1][x], dp[bit - 1][y]);
            }
            else
            {
                 if(dp[bit][y] == dp[bit][x])
                    return dp[bit][y];
            }

        }
    }
}

int main()
{
    int n, m;
    f >> n >> m;
    v.resize(n + 2);
    lant.resize(n + 2);
    for(int i = 2; i <= n; i++)
    {
        int x;
        f >> x;
        tati[i] = x;
        v[x].push_back(i);
        dp[0][i] = x;
    }
    DFS(1, 0);
    creez_dinamica(n);
    for(int i = 0 ; i < m ;i++)
    {
        int x, y;
        f >> x >> y;
        g << query(x, y) << '\n';
    }
}