#include <fstream>
#include <bits/stdc++.h>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int n, m, i, j, t[100005], depth[100005], p, k, x, y, lg, pow2, poz[100005], st, dr;
bool viz[100005];
vector <int> v[100005];
vector <pair<int, int>> eulertour;
struct rangemin
{
    int nod, depth;
}rmq[21][200005];
void dfs(int nod)
{
    viz[nod]=1;
    eulertour.push_back({nod, depth[nod]});
    poz[nod]=eulertour.size();
    for(auto i: v[nod])
        if(viz[i]==0)
        {
            depth[i]=depth[nod]+1;
            dfs(i);
            eulertour.push_back({nod, depth[nod]});
        }
}
int main()
{
    fin>>n>>m;
    for(i=2; i<=n; i++)
    {
        fin>>t[i];
        v[t[i]].push_back(i);
    }
    dfs(1);
    int nr=0;
    for(auto i: eulertour)
    {
        nr++;
        rmq[0][nr].nod=i.first;
        rmq[0][nr].depth=i.second;
    }
    p=2;
    while(p<=nr)
    {
        k++;
        for(i=1; i<=nr-p+1; i++)
            if(rmq[k-1][i].depth<rmq[k-1][i+p/2].depth)
        {
            rmq[k][i].depth=rmq[k-1][i].depth;
            rmq[k][i].nod=rmq[k-1][i].nod;
        }
        else
        {
            rmq[k][i].depth=rmq[k-1][i+p/2].depth;
            rmq[k][i].nod=rmq[k-1][i+p/2].nod;
        }
        p*=2;
    }
    while(m--)
    {
        fin>>x>>y;
        st=min(poz[x], poz[y]);
        dr=max(poz[x], poz[y]);
        lg=dr-st+1;
        p=log2(lg);
        pow2=(1<<p);
        if(rmq[p][st].depth<rmq[p][dr-pow2+1].depth)
            fout<<rmq[p][st].nod<<'\n';
        else
            fout<<rmq[p][dr-pow2+1].nod<<'\n';
    }
    return 0;
}