#include <bits/stdc++.h>
#define usu 317
using namespace std;
ifstream f ("lca.in");
ofstream g ("lca.out");
const int nmax=1e5+3;
int lvl[nmax],t[nmax],t2[nmax],n,ts,a,b;
vector <int> v[nmax];
void dfs(int nod,int ant,int lv)
{
    lvl[nod]=lv;
    t2[nod]=ant;
    if(lv%usu==0) ant=nod;
    for(int i=0;i<v[nod].size();++i) dfs(v[nod][i],ant,lv+1);
}
int main()
{
    ios::sync_with_stdio(false);
    f>>n>>ts;
    for(int i=2;i<=n;++i)
    {
        f>>t[i];
        v[t[i]].push_back(i);
    }
    dfs(1,0,0);
    while(ts--)
    {
        f>>a>>b;
        while(t2[a]!=t2[b])
        {
            if(lvl[a]>lvl[b]) a=t2[a];
            else b=t2[b];
        }
        while(a!=b)
        {
            if(lvl[a]>lvl[b]) a=t[a];
            else b=t[b];
        }
        g<<a<<'\n';
    }
    return 0;
}