#include <bits/stdc++.h>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int tata[200009];
vector <int> v[200009];
int nivel[200009], first[200009];
struct elem
{
    int nod, niv;
}rmq[1000009][22];
void dfs (int x, int t)
{
    for (auto y:v[x])
    {
        if (y!=t)
        {
            nivel[y]=nivel[x]+1;
            dfs (y, x);
        }
    }
}
int cnt=0;
void dfs2 (int nod, int t)
{
    rmq[++cnt][0]={nod, nivel[nod]};
    if (!first[nod]) first[nod]=cnt;
    for (auto y:v[nod])
    {
        if (y!=t)
        {
            dfs2 (y, nod);
            rmq[++cnt][0]={nod, nivel[nod]};
        }
    }
}
elem mini (elem x, elem y)
{
    if (x.niv<=y.niv) return x;
    else return y;
}
int ans (int x, int y)
{
    x=first[x], y=first[y];
    if (x>y) swap (x, y);
    int l=y-x+1;
    int poz=0, nr=1;
    while (2*nr<=l)
    {
        poz++;
        nr*=2;
    }
    elem z=mini (rmq[x][poz], rmq[y-(1<<poz)+1][poz]);
    return z.nod;
}
signed main ()
{
    int n, q;
    f >> n >> q;
    for (int i=2; i<=n; i++)
    {
        f >> tata[i];
        v[tata[i]].push_back(i);
    }
        nivel[1]=1;
    dfs (1, 0);
    dfs2 (1, 0);
    for (int i=1; (1<<i)<=cnt; i++)
    {
        for (int j=1; j+(1<<i)-1<=cnt; j++)
            rmq[j][i]=mini(rmq[j][i-1], rmq[j+(1<<(i-1))][i-1]);
    }
    //for (int i=1; i<=cnt; i++) cout << rmq[i][0].nod << ' ';
    //cout <<cnt;
    while (q--)
    {
        int x, y;
        f >> x >> y;
        g << ans(x,y) << '\n';
    }
}