#include <bits/stdc++.h>

using namespace std;

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

int n, m, cnt;
vector<int> v[200100];
int first[200200];
struct euler
{
    int nod;
    int nivel;
};
euler parcurgere[200200];
int nivel[200100];
int logaritm[200200];
int rmq[200100][19]; /// pozitia corespunzatoare in parcurgerea euler celui mai mic nivel
void dfs(int nod, int tata)
{
    nivel[nod] = nivel[tata] + 1;
    parcurgere[++cnt].nod = nod;
    parcurgere[cnt].nivel = nivel[nod];
    for(int it = 0; it != v[nod].size(); it++)
    {
        dfs(v[nod][it], nod);
        parcurgere[++cnt].nod = nod;
        parcurgere[cnt].nivel = nivel[nod];
    }
}

int Merge(int a, int b)
{
    if(parcurgere[a].nivel < parcurgere[b].nivel)
    {
        return a;
    }
    else
        return b;
}

int lca(int a, int b)
{
    if(a > b)
        swap(a,b);
    int logg = logaritm[b-a+1];
    return Merge(rmq[a][logg], rmq[b - (1 << logg) + 1][logg]);
}

int main()
{
    fin >> n >> m;
    for(int i = 2; i <= n; i ++)
    {
        int val;
        fin >> val;
        v[val].push_back(i);
    }
    dfs(1, 0);
    for(int i = 1; i <= cnt; i ++)
    {
        if(first[parcurgere[i].nod] == 0)
        {
            first[parcurgere[i].nod] = i;
        }
    }
    for(int i = 1; i <= cnt; i ++)
    {
        rmq[i][0] = i;
    }
    for(int i = 2; i <= cnt; i ++)
    {
        logaritm[i] = logaritm[i/2] + 1;
    }
    for(int j = 1; (1 << j) <= cnt; j ++)
    {
        for(int i = 1; i + (1 << j) - 1 <= cnt; i ++)
        {
            rmq[i][j] = Merge(rmq[i][j-1], rmq[i + (1 << (j-1))][j-1]);
        }
    }
    ///fout << parcurgere[lca(first[1],first[1])].nod;
    ///fout << '\n';
    while(m--)
    {
        int l, r;
        fin >> l >> r;
        fout << parcurgere[lca(first[l], first[r])].nod << '\n';
    }
    return 0;

}