#include <bits/stdc++.h>
#define NM 100005
using namespace std;
ifstream fin ("lca.in");
ofstream fout ("lca.out");
int n, m, t[NM], niv[NM];//nivel, nod
int ap[NM];//prima ap
vector<pair<int,int>> v[int(log2(4*NM))+2];
vector<int> g[NM];
bitset<NM> viz;
void euler(int nod)
{
    viz[nod] = 1;
    v[0].push_back({niv[nod], nod});
    ap[nod] = v[0].size()-1;
    for(auto it:g[nod])
        if(!viz[it])
        {
            niv[it] = niv[nod] + 1;
            euler(it);
            v[0].push_back({niv[nod], nod});
        }
}
void build_rmq()
{
    int N = v[0].size();
    for(int i=1; (1<<i)<=N; i++)
    {
        v[i].push_back({0, 0});
        for(int j=1; j<=N-(1<<i)+1; j++)
        {
            if(v[i-1][j].first < v[i-1][j+(1<<(i-1))].first)
                v[i].push_back(v[i-1][j]);
            else v[i].push_back(v[i-1][j+(1<<(i-1))]);
        }
    }
}
int query(int x, int y)
{
    x = ap[x], y = ap[y];
    if(x > y)
        swap(x, y);
    int p = log2(y-x+1);
    if(v[p][x].first < v[p][y-(1<<p)+1].first)
        return v[p][x].second;
    else return v[p][y-(1<<p)+1].second;
}
void read();
int main()
{
    read();
    niv[1] = 1;
    v[0].push_back({0, 0});
    euler(1);
    build_rmq();
    while(m--)
    {
        int x, y;
        fin >> x >> y;
        fout << query(x, y) << '\n';
    }
    return 0;
}
void read()
{
    fin >> n >> m;
    for(int i=2; i<=n; i++)
    {
        fin >> t[i];
        //g[i].push_back(t[i]);
        g[t[i]].push_back(i);
    }
}