#include <cstdio>
#include <queue>
#include <algorithm>
using namespace std;

const int dim=100000;

struct nod
{
    int x;
    queue <nod *>f;
}*a[dim+1];

int n,m,e,poz[dim+1],eulerv[2*dim],ad[2*dim]; //prb+euler
int lg[2*dim],rmq[2*dim][18]; //rmq

void read()
{
    freopen("lca.in","r",stdin);
    int x;
    scanf("%d%d",&n,&m);
    a[1]=new nod;
    a[1]->x=1;
    for(int i=2;i<=n;++i)
    {
        scanf("%d",&x);
        a[i]=new nod;
        a[i]->x=i;
        a[x]->f.push(a[i]);
    }
}

void eulerf(nod *nd,int adancime)
{
    eulerv[++e]=nd->x;
    ad[e]=adancime;
    poz[nd->x]=e;
    while(!nd->f.empty())
    {
        eulerf(nd->f.front(),adancime+1);
        eulerv[++e]=nd->x;
        ad[e]=adancime;
        nd->f.pop();
    }
}

void rmqf()
{
    int i,k;
    for(i=2;i<=e;++i)
    {
        lg[i]=lg[i>>1]+1;
    }
    for(i=1;i<=e;++i)
    {
        rmq[i][0]=i;
    }
    for(k=1;(1<<k)<=e;++k)
    {
        for(i=1;i<=e-(1<<k)+1;++i)
        {
            if(ad[rmq[i][k-1]]<ad[rmq[i+(1<<(k-1))][k-1]])
            {
                rmq[i][k]=rmq[i][k-1];
            }
            else
            {
                rmq[i][k]=rmq[i+(1<<(k-1))][k-1];
            }
        }
    }
}

int main()
{
    read();
    eulerf(a[1],0);
    freopen("lca.out","w",stdout);
    rmqf();
    int x,y,diff;
    while(m)
    {
        --m;
        scanf("%d%d",&x,&y);
        x=poz[x];
        y=poz[y];
        if(x>y)
        {
            diff=lg[x-y+1];
            if(ad[rmq[y][diff]]<ad[rmq[x+1-(1<<diff)][diff]])
            {
                printf("%d\n",eulerv[rmq[y][diff]]);
            }
            else
            {
                printf("%d\n",eulerv[rmq[x+1-(1<<diff)][diff]]);
            }
        }
        else
        {
            diff=lg[y-x+1];
            if(ad[rmq[x][diff]]<ad[rmq[y+1-(1<<diff)][diff]])
            {
                printf("%d\n",eulerv[rmq[x][diff]]);
            }
            else
            {
                printf("%d\n",eulerv[rmq[y+1-(1<<diff)][diff]]);
            }
        }
    }
    return 0;
}