#include <bits/stdc++.h>

using namespace std;

///dfs, aint

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

const int nmax = 1000;
int v[nmax + 5], prima_poz[nmax + 5];
int n;
vector <int> a[nmax + 5];

struct structura{
    int adancime, nod;
};
structura Euler[2 * nmax + 5], aint[4 * nmax + 5];
int nr_elemente;

void euler(int k, int depth)
{
    ++nr_elemente;
    Euler[nr_elemente].adancime = depth;
    Euler[nr_elemente].nod = k;
    if(prima_poz[k] == 0)
        prima_poz[k] = nr_elemente;
    for(auto i : a[k])
    {
        euler(i, depth + 1);
        ++nr_elemente;
        Euler[nr_elemente].adancime = depth;
        Euler[nr_elemente].nod = k;
    }
}

void build(int nod, int l, int r)
{
    if(l != r)
    {
        int m=(l + r)/2;
        build(2*nod, l, m);
        build(2*nod + 1, m + 1, r);
        if(aint[2 * nod].adancime > aint[2 * nod + 1].adancime)
        {
            aint[nod].adancime = aint[2 * nod + 1].adancime;
            aint[nod].nod = aint[2 * nod + 1].nod;
        }
        else
        {
            aint[nod].adancime = aint[2 * nod].adancime;
            aint[nod].nod = aint[2 * nod].nod;
        }
    }
    else
    {
        ///l = r
        aint[nod].adancime = Euler[l].adancime;
        aint[nod].nod = Euler[l].nod;
    }
}

structura mini(structura a, structura b)
{
    if(a.adancime < b.adancime)
        return a;
    else
        return b;
}

structura q(int nod, int l, int r, int ql, int qr)
{
    if(l > qr || r < ql || r < l)
    {
        return {nmax, -1};
    }
    else
    {
        if( ql <= l && ql <= r && qr >= l && qr >= r)
        {
            ///int [l, r] este inclus in [ql, qr]
            return aint[nod];
        }
        else
        {
            int m = (l + r)/2;
            return mini(q(2*nod, l, m, ql, qr), q(2*nod + 1, m + 1, r, ql, qr));
        }
    }
}

int main()
{
    int Q, i, x, y;
    f >> n >> Q;
    for(i = 1; i <= n - 1; ++i)
    {
        f >> x;
        a[x].push_back(i + 1);
    }
    euler(1, 0);
    build(1, 1, nr_elemente);
    for(i = 1; i <= Q; ++i)
    {
        f >> x >> y;
        if(prima_poz[x] < prima_poz[y])
            g << q(1, 1, nr_elemente, prima_poz[x], prima_poz[y]).nod << "\n";
        else
            g << q(1, 1, nr_elemente, prima_poz[y], prima_poz[x]).nod << "\n";
    }
    return 0;
}