#include<stdio.h>

#define Nmax 100005
#define Nlog 20
#define inf 0x3f3f3f

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

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


int lca(int a,int b)
{
    int sol,misc,aux,dif,k;
    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[k][a];
    if (L[sol] > L[ R[k][a+misc] ])
        sol=R[k][a+misc];
        
    return E[sol];
}

int solve()
{
    int ok,x,max;
    for(int i=m;i;--i)
        {
        ok=1;
        max=-inf;
        for(int j=i+1;j<=m;++j)
            {
            x=lca(s[i],s[j]);
            if (x==i || x==j)
                {
                if (max < d[j])
                    max = d[j];
                ok=0;
                }
            }
            
        if (ok)
            d[i]=s[i];
        else
            d[i]=d[i]-max;
        }
        
    for(int i=1;i<=m;++i)
        printf("%d\n",d[i]);
}

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

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 i)
{
    nod *p=new nod;
    p->info=i;
    p->urm=inc;
    inc=p;
}

void cit()
{
    int a;
  //  freopen("treegame.in","r",stdin);
 //   freopen("treegame.out","w",stdout);
    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);
        }
  //  for(int i=1;i<=m;++i)
  //      scanf("%d",&s[i]);
}

int main()
{
    int a,b;
    cit();
    
    df(1,0);
    
    rmq();
    
//    solve();
        
    for(;m;--m)
        {
        scanf("%d%d",&a,&b);
        printf("%d\n",lca(a,b));
        }
    return 0;
}