#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>
#define DIM 100010
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int p[25],lg[2*DIM];
pair<int,int> D[20][2*DIM];
int n,m,a,b,i,k,tata;
vector<int> L[DIM];
int APARITIE[DIM];
void dfs(int nod, int niv){
    D[0][++k].first=niv;
    D[0][k].second=nod;
    APARITIE[nod]=k;
    for(int i=0;i<L[nod].size();i++){
        int vecin=L[nod][i];
        dfs(vecin,niv+1);
        D[0][++k].first=niv;
        D[0][k].second=nod;
    }
}
void precalculare_puteri(){
    p[0]=1;
    for(int i=1; p[i-1] <= 2*n-1;i++)
        p[i]=p[i-1]*2;
}
void dinamica(){
    for(int i=1;p[i]<=2*n-1;i++)
        for(int j=1;j<=2*n-1;j++){
            if(j+p[i-1]<=2*n-1){
                if(D[i-1][j+p[i-1]].first < D[i-1][j].first)
                    D[i][j]=D[i-1][j+p[i-1]];
                else
                    D[i][j]=D[i-1][j];
            }
            else
                D[i][j]=D[i-1][j];
        }
}
void logaritm(){
    lg[1]=0;
    for(int i=2;i<200005;i++)
            lg[i]=lg[i/2]+1;
}
int rmq(int a, int b){
    if(D[lg[b-a]][a].first < D[lg[b-a]][b-p[lg[b-a]]+1].first)
        return D[lg[b-a]][a].second;
    else
        return D[lg[b-a]][b-p[lg[b-a]]+1].second;
}
int main(){
    fin>>n>>m;
    for(i=2;i<=n;i++){
        fin>>tata;
        L[tata].push_back(i);
    }
    dfs(1,1);
    precalculare_puteri();
    dinamica();
    logaritm();
    for(i=1;i<=m;i++){
        fin>>a>>b;
        a=APARITIE[a];
        b=APARITIE[b];
        if(a>b)
            swap(a,b);
        fout<<rmq(a,b)<<"\n";
    }
return 0;
}