#include <iostream>
#include <fstream>
#include <vector>

#define NMAX 100001

using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

int n, m, L, rmq[2*NMAX][30], log[2*NMAX];
int euler[2*NMAX], niv[NMAX], first[NMAX];
vector <int> v[NMAX];

void citire()
{
    fin>>n>>m;
    int x;
    for(int i=2;i<=n;i++)
    {
        fin>>x;
        v[x].push_back(i);
    }
}

void formare_euler(int nod, int nivel)
{
    euler[++L]=nod;
    niv[L]=nivel;
    first[nod]=L;
    for(unsigned int i=0;i<v[nod].size();i++)
    {
        formare_euler(v[nod][i],nivel+1);
        euler[++L]=nod;
        niv[L]=nivel;
    }
}

void range()
{
    for(int i=1;i<=L;i++)
        rmq[i][0]=i;
    for(int j=1;(1<<j)<=L;j++)
    {
        for(int i=1;i+(1<<j)-1<=L;i++)
        {
            if(niv[rmq[i][j-1]]<niv[rmq[i+(1<<(j-1))][j-1]])
                rmq[i][j]=rmq[i][j-1];
            else
                rmq[i][j]=rmq[i+(1<<(j-1))][j-1];
        }
    }
}

int lca(int x, int y)
{
    int a=first[x], b=first[y];
    if(a>b)
        swap(a,b);
    int dif, l1, l2, sol1, sol2;
    dif=b-a+1;
    l1=log[dif];
    sol1=rmq[a][l1];
    l2=dif-(1<<l1);
    sol2=rmq[a+l2][l1];
    if(niv[sol1]>niv[sol2])
        sol1=sol2;
    return euler[sol1];
}

int main()
{
    citire();
    formare_euler(1,1);
    range();
    int x, y;
    log[1]=0;
    for(int i=2;i<=L;i++)
        log[i]=log[i/2]+1;
    while(m)
    {
        m--;
        fin>>x>>y;
        fout<<lca(x,y)<<'\n';
    }
    return 0;
}