#include <iostream>
#include <vector>
#include <algorithm>
#include <limits>
#include <numeric>
#include <cstring>
#include <string>
#include <queue>
#include <set>
#include <cmath>
#include <fstream>
#include <cstdlib>
#include <map>
#define pb push_back
#define mp make_pair
#define INF numeric_limits<int>::max()
#define bit(x) (-x)&x
#define int64 long long
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
vector< vector<int> > a;
vector<int> p,eul,lvl,tree;
int n,k;
void dfs(int x,int level)
{
    lvl[++k]=level;
    eul[k]=x;
    p[x]=k;
    for(vector<int>::iterator i=a[x].begin();i!=a[x].end();i++)
    {
        dfs(*i,level+1);
        lvl[++k]=level;
        eul[k]=x;
    }
}
void update(int x,int left,int right)
{
    if(left==right)
        tree[x]=left;
    else{
        int mid=(left+right)/2;
        update(2*x,left,mid);
        update(2*x+1,mid+1,right);
        tree[x]=(lvl[ tree[2*x] ] > lvl[ tree[2*x+1] ] ? tree[2*x+1] : tree[2*x]);
    }
}
int sol,q;
void query(int x,int left,int right,int a,int b)
{
    if(a<=left && b>=right)
        sol= (lvl[ sol ] > lvl[ tree[x] ] ? tree[x] : sol);
    else{
        int mid=(left+right)/2;
        if(a<=mid)
            query(2*x,left,mid,a,b);
        if(b>mid)
            query(2*x+1,mid+1,right,a,b);
    }
}
int LCA(int x,int y)
{
    sol=0;
    x=p[x];
    y=p[y];
    if(x>y)
        swap(x,y);
    query(1,1,k,x,y);
    return eul[sol];
}
int main()
{
    in>>n>>q;
    a=vector< vector<int> > (n+1);
    p=vector<int> (n+1);
    lvl=eul=vector<int> (2*n+2);
    for(int i=2;i<=n;i++)
    {
        int x;
        in>>x;
        a[x].pb(i);
    }
    dfs(1,1);
    tree=vector<int> (4*k+1);
    update(1,1,k);
    lvl[0]=INF;
    for(;q;q--)
    {
        int x,y;
        in>>x>>y;
        out<<LCA(x,y)<<'\n';
    }
    return 0;
}