#define logn 19
#include <fstream>
#include <math.h>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

int n,m,i,t,x,y,lg,l,j;
int lev[200001];
int euler[200001];
int first[200001];
int rmq[19][200001];
int logg[200001];
typedef struct celula{

int nod;
celula *next;

}*lista;

lista graf[100001],p,a;


void dfs(int nod, int nivel, int tata)
{
    ++lg;

    euler[lg]=nod;
    lev[lg]=nivel;
    first[nod]=lg;

    for(lista p=graf[nod]; p; p=p->next)
        if(p->nod!=tata)
        {
            dfs(p->nod, nivel+1,nod);

            ++lg;
            euler[lg]=nod;
            lev[lg]=nivel;
        }
}

int query(int x, int y)
{
    int i1=0, i2=0;
    if(x>y) swap(x,y);
    int p=logg[y-x+1];
    int l=(1<<p);
    i1=rmq[p][x]; i2=rmq[p][y-l+1];

    if(lev[i1]<lev[i2]) return euler[i1];
    else return euler[i2];

}


int main()
{
    fin>>n>>m;
    for(i=2;i<=n;++i)
    {

        fin>>t;


        a=new celula;
        a->nod=t;
        a->next=graf[i];
        graf[i]=a;

        a=new celula;
        a->nod=i;
        a->next=graf[t];
        graf[t]=a;
    }


    dfs(1,1,0);


    for(i=2;i<=lg;++i)
        logg[i]=logg[i/2]+1;

    for(i=1;i<=lg;++i)
        rmq[0][i]=i;


    for(i=1, l=2 ;l<=lg;++i, l*=2)
        for(j=1;j+l-1<=lg;++j)
    {
        if(lev[rmq[i-1][j]]<lev[rmq[i-1][j+l/2]])
            rmq[i][j]=rmq[i-1][j];
        else rmq[i][j]=rmq[i-1][j+l/2];
    }

    for(i=1;i<=m;++i)
    {
        fin>>x>>y;

        fout<<query(first[x],first[y])<<"\n";
    }


    return 0;
}