#include<iostream>
#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
struct node{
    int depth,ind;
    node(){
        depth=0;
        ind=0;
    }
    node(int d,int i){
        depth=d;
        ind=i;
    }
    bool operator<(const node& other)
    const {
        return depth<other.depth;
    }
    void operator=(const node& other)
    {
        depth=other.depth;
        ind=other.ind;
    }
};
const int NMAX=200007,LOGMAX=20;
int n,m,nod;
int dad[NMAX];
vector<int> sons[NMAX];
vector<node> euler;
node rmq[NMAX][LOGMAX];//rmq[i][j]=min pe i,i+1,...,i+2^j-1
int deep[NMAX];
int poz[NMAX];
int logn;
void dfs(int nod)
{
    node nodat(deep[nod],nod);
    poz[nod]=euler.size()+1;
    euler.push_back(nodat);
    for(auto w:sons[nod])
    {
        deep[w]=deep[nod]+1;
        dfs(w);
        euler.push_back(nodat);
    }
}
int get_exp(int nr)
{
    int pt=1;
    for(int i=0;i<=LOGMAX+1;i++)
    {
        if(pt>nr)
        {
            return i-1;
        }
        pt=pt<<1;
    }
    return 0;
}
int main()
{
    in>>n>>m;
    logn=get_exp(2*n);
    for(int i=2;i<=n;i++)
    {
        in>>dad[i];
        sons[dad[i]].push_back(i);
    }
    deep[1]=0;
    dfs(1);
    int it=1;
    for(auto w:euler)
    {
        rmq[it][0]=w;
        it++;
    }
    for(int j=1;j<logn;j++)
    {
        for(int i=1;i<=it-(1<<j);i++)
        {
            rmq[i][j]=min(rmq[i][j-1],rmq[i+(1<<(j-1))][j-1]);
        }
    }
    int a,b;
    for(int i=1;i<=m;i++)
    {
        in>>a>>b;
        int rig=max(poz[a],poz[b]);
        int lef=min(poz[a],poz[b]);
        int put=get_exp(rig-lef+1);
        node aux=min(rmq[lef][put],rmq[rig-(1<<put)+1][put]);
        out<<aux.ind<<"\n";
    }
}