#include <bits/stdc++.h>
#define nmax 100005
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

int first_app[nmax], rmq[nmax][30], numere[3 * nmax], lungime_euler, n, m, start[nmax], ordine[nmax], ord;
vector <int> graph[nmax];
bool vizat[nmax];

void citire()
{
    int x, i;
    for(i = 2; i <= n; i++)
        fin >> x, graph[x].push_back(i);
}

void dfs(int nod)
{
    vizat[nod] = 1;
    ordine[nod] = ord, start[ord] = nod, ord++;
    numere[lungime_euler] = ordine[nod];
    first_app[nod] = lungime_euler;
    lungime_euler++;

    unsigned i, len;
    len = graph[nod].size();
    for(i = 0; i < len; i++)
    {
        if(!vizat[graph[nod][i]])
        {
            dfs(graph[nod][i]);
            numere[lungime_euler] = ordine[nod], lungime_euler++;
        }
    }
}

void sparse(int logeuler)
{
    int i, j, z, t;
    for(i = 0; i < lungime_euler; i++)
        rmq[i][0] = numere[i];
    for(j = 1; j <= logeuler; j++)
    {
        t = (1 << j);
        z = (1 << (j - 1));
        for(i = 0; i + t <= lungime_euler; i++)
        {
            if(start[rmq[i][j - 1]] < start[rmq[i + z][j - 1]])
                rmq[i][j] = rmq[i][j - 1];
            else
                rmq[i][j] = rmq[i + z][j-1];
        }
    }
}

int get_lg(int a)
{
    int x = 0;
    while(a > 1)
    {
        a = (a >> 1);
        x++;
    }
    return x;
}

int functie(int a, int b)
{
    int k;
    k = get_lg(b - a);
    if(start[rmq[a][k]] < start[rmq[b - (1 << k) +1][k]])
        return start[rmq[a][k]];
    else
        return start[rmq[b - (1 << k) + 1][k]];
}

int main()
{
    int i, x, y;
    fin >> n >> m;
    citire();
    dfs(1);
    sparse(get_lg(lungime_euler));
    for(i = 0; i < m; i++)
    {
        fin >> x >> y;
        if(first_app[x] < first_app[y])
            fout << functie(first_app[x], first_app[y]) << '\n';
        else
            fout << functie(first_app[y], first_app[x]) << '\n';
    }
    return 0;
}