#include <iostream>
#include<fstream>
#include<vector>
using namespace std;
int x[100001],i,j,k,l,n,m,e[200002],nv[100001],N,o,p,O,first[100001];
int A,B;
int D[20][100001];
vector<int> a[100001];
void euler(int i)
{
    D[0][k++]=i;if(!first[i])first[i]=k-1;
    if(x[i]>0)
    {
        for(int j10=0;j10<x[i];++j10)
        {
            euler(a[i][j10]);
            D[0][k++]=i;
            //cout<<a[i][j]<<" ";
        }
    }
}
int mn(int a,int b)
{
    if(a>b)return b;
    return a;
}
int log2(int a)
{
    if(a==0)return 0;
    if(a==1)return 0;
    int k10;
    for(k10=0;(1<<k10)<a;++k10);
    if((1<<k10)>a)--k10;
    return k10;
}
int main()
{
    ifstream f("lca.in");
    f>>n>>m;nv[1]=0;
    for(i=1;i<n;++i)
    {
        f>>l;nv[i+1]=nv[l]+1;
        a[l].push_back(i+1);
        ++x[l];
    }
    k=1;
    euler(1);
    N=log2(k)+1;
    for(i=1;i<N;++i)
    {
        for(j=1;j<k;++j)
        {
            D[i][j]=mn(D[i-1][j],D[i-1][j+(1<<(i-1))]);
        }
    }
    ofstream g("lca.out");
    for(l=0;l<m;++l)
    {
        f>>o>>p;
        A=first[o];B=first[p];
        if(A>B)swap(A,B);
        o=log2(B-A);//cout<<A<<" "<<B<<" "<<o<<" ";
        p=mn(D[o][A],D[o][B-(1<<o)+1]);
        //cout<<D[o][B-(1<<o)+1]<<" "<<D[o][A]<<'\n';
        g<<p<<'\n';
    }
    f.close();
    g.close();
    return 0;
}