#include <fstream>
#include <vector>
#include <cmath>
#define NM 100005

using namespace std;

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

int n, q;

vector <int> G[NM];
vector <int> N;
vector <int> Val;

int M[2*NM][20], P[25];

int Valid[NM], Poz[NM];

void DFS(int x, int lv)
{
    int sz=G[x].size(), i;
    N.push_back(lv);
    Val.push_back(x);
    Poz[x]=N.size()-1;
    for (i=0; i<sz; i++)
    {
        if (Valid[G[x][i]]==0)
        {
            Valid[G[x][i]]=1;
            DFS(G[x][i], lv+1);
            N.push_back(lv);
            Val.push_back(x);
        }
    }
}

void Preprocesare()
{
    int k = log(N.size())/log(2);
    int sz = N.size(), loc, i, j;
    for (i=0; i<sz; i++)
        M[i][0]=i;
    loc=1;
    for (j=1; j<=k; j++)
    {
        for (i=0; i<sz-loc+1; i++)
        {
            if (N[M[i][j-1]]<N[M[i+loc][j-1]])
                M[i][j]=M[i][j-1];
            else
                M[i][j]=M[i+loc][j-1];
        }
        loc*=2;
    }
}

void Put2()
{
    int i;
    P[0]=1;
    for (i=1; i<=20; i++)
        P[i]=P[i-1]*2;
}

void RMQ()
{
    int x, y, i, d, a, b;
    for (i=1; i<=q; i++)
    {
        fin>>a>>b;
        x=min(Poz[a], Poz[b]);
        y=max(Poz[a], Poz[b]);
        d=log(y-x+1)/log(2);
        if (N[M[x][d]]<N[M[y-P[d]+1][d]])
            fout<<Val[M[x][d]];
        else
            fout<<Val[M[y-P[d]+1][d]];
        fout<<'\n';
    }
}

int main()
{
    int i, x, j;
    fin>>n>>q;
    for (i=2; i<=n; i++)
    {
        fin>>x;

        G[x].push_back(i);
        G[i].push_back(x);
    }
    Valid[1]=1;
    DFS(1, 0);
    Preprocesare();
    Put2();
    RMQ();
    return 0;
}