#include<fstream>
#include<vector>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
pair<int,int> niv[20][200001];
int i,t,n,m,a,b,p[200001],aux,d[100001],nr,val[200010];
vector<int> v[100001];
void dfs(int nod,int lvl)
{
    d[nod]=++nr;niv[0][nr].first=lvl;val[nr]=nod;niv[0][nr].second=nr;
    for(auto it:v[nod]){dfs(it, lvl+1);niv[0][++nr].first=lvl;val[nr]=nod;niv[0][nr].second=nr;}
}
int main()
{
    fin>>n>>m;
    for(i=2;i<=n;i++)
    {
        fin>>a;
        v[a].push_back(i);
    }
    dfs(1,0);
    for(i=2;i<=nr;i++) p[i]=p[i/2]+1;
    for(t=1;t<=p[nr];t++)for(i=1;i<=nr;i++)
    {
        niv[t][i]=niv[t-1][i];
        if(i+(1<<(t-1))<=nr&&niv[t][i].first>niv[t-1][i+(1<<(t-1))].first) niv[t][i]=niv[t-1][i+(1<<(t-1))];
    }
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;
        a=d[a];b=d[b];
        if(a>b) swap(a,b);
        aux=p[(b-a+1)];
        if(niv[aux][a].first<niv[aux][b-(1<<aux)+1].first)
            fout<<val[niv[aux][a].second]<<"\n";
        else
            fout<<val[niv[aux][b-(1<<aux)+1].second]<<"\n";
    }
    return 0;
}