#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <algorithm>
#include <vector>
#define LIM 1<<17
/// TONI BO$$ was here
/// #MLC

using namespace std;
char BUF[LIM];
int poz;

inline char getChar(){
    poz++;
    if(poz>=LIM){
        fread(BUF,LIM,1,stdin);
        poz=0;
    }
    return BUF[poz];
}

inline int getNr(){
    int r=0, semn=1;
    char ch=getChar();
    while(isdigit(ch)==0 && ch!='-') ch=getChar();
    if(ch=='-'){
        semn=-1;
        ch=getChar();
    }
    while(isdigit(ch)!=0){
        r=r*10+semn*(ch-'0');
        ch=getChar();
    }
    return r;
}

vector <int> L[100001];
int f[100001],euler[200001],level[200001] ,nr,ap[100001],lg2[200001];
pair <int, int> rmq[200001][18];

void dfs(int i, int lev)
{
    f[i]=1;
    euler[++nr]=i;
    level[nr] = lev;
    for(auto it : L[i])
        if(!f[it])
        {
            dfs(it, lev + 1);
            euler[++nr]=i;
            level[nr] = lev;
        }
}

int main()
{
    int n,m,i,x,y,p2,ct,a,b;
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    n=getNr();
    m=getNr();
    for(i=2; i<=n; i++)
    {
        x=getNr();
        L[x].push_back(i);
        L[i].push_back(x);
    }
    dfs(1, 1);
    for(i=1; i<=nr; i++)
        if(!ap[euler[i]])
            ap[euler[i]]=i;
    for(i=1; i<=nr; i++)
        rmq[i][0]={level[i], euler[i]};
    for(ct=1; (1<<ct)<=nr; ct++)
        for(i=(1<<ct); i<=nr; i++)
            if(rmq[i][ct-1].first < rmq[i-(1<<(ct-1))][ct-1].first)
                rmq[i][ct] = rmq[i][ct-1];
            else
                rmq[i][ct] = rmq[i-(1<<(ct-1))][ct-1];
    for(i=2; i<=nr; i++)
        lg2[i]=lg2[i/2]+1;
    while(m--)
    {
        x=getNr();
        y=getNr();
        a=min(ap[x],ap[y]);
        b=max(ap[x],ap[y]);
        if(rmq[a+(1<<lg2[b-a+1])-1][lg2[b-a+1]].first < rmq[b][lg2[b-a+1]].first)
            printf("%d\n",rmq[a+(1<<lg2[b-a+1])-1][lg2[b-a+1]].second);
        else
            printf("%d\n",rmq[a+(1<<lg2[b-a+1])-1][lg2[b-a+1]].second);
    }

    return 0;
}