#include<stdio.h>

#define Nmax 100005
#define Nlog 25

struct nod
{
    int info;
    nod *urm;
} *l[Nmax];

int n,E[Nmax<<1],L[Nmax<<1],F[Nmax],np;
int R[Nmax<<1][Nlog],lg[Nmax<<1];

int lca(int a,int b)
{
    int aux,k,dif,misc,sol;
    a=F[a];
    b=F[b];
    if (a>b)
        {
        aux=a; 
        a=b;
        b=aux;
        }
        
    dif=b-a+1;
    k=lg[dif];
    misc=dif - (1<<k);
    
    sol=R[a][k];
    if (L[sol] > L[ R[a+misc][k] ])
        sol=R[a+misc][k];

    return E[sol];
}

void rmq()
{
    for(int i=2;i<=np;++i)
        lg[i]=lg[i>>1]+1;
    for(int i=1;i<=np;++i)
        R[i][0]=i;
        
    for(int i=1;(1<<i)<np;++i)
        for(int j=1 , p=(1<<(i-1)); j <= np - (1<<i);++j)
            {
            R[j][i]=R[j][i-1];
            if (L[ R[j][i] ] > L[ R[ j+p ][i-1] ])
                R[j][i] = R[j+p][i-1];
            }
}

void df(int k,int niv)
{
    E[++np]=k;
    L[np]=niv;
    F[k]=np;
    
    for(nod *t=l[k]; t ; t=t->urm)
        {
        df(t->info,niv+1);
        
        E[++np]=k;
        L[np]=niv;
        }
}

void add(nod *&inc,int inf)
{
    nod *p=new nod;
    p->info=inf;
    p->urm=inc;
    inc=p;
}

int main()
{
    int a,b,m;
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i=2;i<=n;++i)
        {
        scanf("%d",&a);
        add(l[a],i);
        }
        
    df(1,0);
    
    rmq();
    
    for(;m;--m)
        {
        scanf("%d%d",&a,&b);
        printf("%d\n",lca(a,b));
        }
    return 0;
}