#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
const int maxn = 100005;
vector <int> v[maxn];
vector <int> euler;
int aint[maxn * 8];
int firstap[maxn];
int nivel[maxn];

void dfs(int nod, int niv)
{
    nivel[nod] = niv;
    euler.push_back(nod);
    for(auto it : v[nod])
    {
        dfs(it, niv + 1);
        euler.push_back(nod);
    }
}

void update(int nod, int st, int dr, int poz, int val)
{
    if(poz < st || poz > dr)
        return;
    if(st == dr)
    {
        aint[nod] = val;
        return;
    }
    int mij = (st + dr) / 2;
    update(nod * 2, st, mij, poz, val);
    update(nod * 2 + 1, mij + 1, dr, poz, val);
    if(nivel[aint[nod * 2]] < nivel[aint[nod * 2 + 1]])
        aint[nod] = aint[nod * 2];
    else
        aint[nod] = aint[nod * 2 + 1];
}

int query(int nod, int st, int dr, int x, int y)
{
    if(st > y || dr < x)
        return 0;
    if(x <= st && dr <= y)
        return aint[nod];
    int mij = (st + dr) / 2;
    int q1 = query(nod * 2, st, mij, x, y);
    int q2 = query(nod * 2 + 1, mij + 1, dr, x, y);
    if(nivel[q1] < nivel[q2])
        return q1;
    else
        return q2;
}

int main()
{
    int n, m;
    in >> n >> m;
    for(int i = 2; i <= n; i++)
    {
        int x;
        in >> x;
        v[x].push_back(i);
    }
    dfs(1, 0);
    int poz = 0;
    for(auto it : euler)
    {
        update(1, 1, n * 2 - 1, ++poz, it);
        if(firstap[it] == 0)
            firstap[it] = poz;
    }
    nivel[0] = (1 << 30);
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        in >> x >> y;
        x = firstap[x];
        y = firstap[y];
        out << query(1, 1, n * 2 - 1, min(x, y), max(x, y)) << "\n";
    }
    return 0;
}