#include <fstream>
#include <vector>
#include <cmath>

#define NMAX 100005
#define log(a) (int)log2(a)
#define LOGNMAX (int)log2(2*NMAX)+2
using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");


int n, m;
int x;
int firstApp[NMAX];
int rmq[LOGNMAX][2*NMAX];
vector<int>graph[NMAX];
vector<int>euler;

void formEuler(int nod=1, int parent=0){
    firstApp[nod]=euler.size();
    euler.push_back(nod);
    for(auto &v:graph[nod])
        if(v!=parent){
            formEuler(v, nod);
            euler.push_back(nod);
        }
}

void citire(){
    f>>n>>m;
    for(int i=1; i<n; i++){
        f>>x;
        graph[i+1].push_back(x);
        graph[x].push_back(i+1);
    }
}

void formRMQ(){
    for(int j=0; j<euler.size(); j++)
        rmq[0][j] = euler[j];
    for(int j=1; (1<<j)<=euler.size(); j++)
        for(int i=0; i+(1<<j)<euler.size();i++)
            rmq[j][i] = min(rmq[j-1][i], rmq[j-1][i+(1<<(j-1))]);
}

void query(){
    int x, y;
    for(int i=1; i<=m; i++){
        f>>x>>y;

        int a = firstApp[x];
        int b = firstApp[y];

        if(a>b)
            swap(a, b);
        int val = log(b-a+1);
        g<<min(rmq[val][a], rmq[val][b-(1<<val)+1])<<'\n';

    }
}
int main()
{
    citire();
    formEuler();
    formRMQ();
    query();
    return 0;
}