#include<bits/stdc++.h>
using namespace std;
const int NMAX=100005;
vector<int>v[NMAX];
int p[NMAX],d[NMAX],dmax,h,p_sq[NMAX],d_sq[NMAX];
void dfs(int nod)
{
    for(auto it:v[nod])
    {
            d[it]=d[nod]+1;
            dmax=max(dmax,d[it]);
            dfs(it);
    }
}
void dfs_sq(int nod)
{
    for(auto it:v[nod])
    {
        d[it]=d[nod]+1;
        d_sq[it]=d_sq[nod];
        p_sq[it]=p_sq[nod];
        if(d[it]%h==1)
            p_sq[it]=nod,d_sq[it]++;
        dfs(it);
    }
}
int naivelca(int a,int b)
{
    if(a==b)return a;
    if(d[a]>d[b])swap(a,b);
    if(d[a]<d[b])return naivelca(a,p[b]);
    if(d[a]==d[b])return naivelca(p[a],p[b]);
}
int lca(int a,int b)
{
    if(p_sq[a]==p_sq[b])
        return naivelca(a,b);
    if(d_sq[a]>d_sq[b])swap(a,b);
    if(d_sq[a]<d_sq[b])return lca(a,p_sq[b]);
    return lca(p_sq[a],p_sq[b]);
}
int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    int m,n,k,a,b,i;
    cin>>n>>m;
    for(i=2;i<=n;i++)
        {
            cin>>p[i];
            v[p[i]].push_back(i);
        }
    d[1]=1;
    d_sq[1]=1;
    dfs(1);

    h=(int)sqrt(dmax);
    dfs_sq(1);
    for(i=1;i<=m;i++)
    {
        cin>>a>>b;
        cout<<lca(a,b)<<'\n';
    }
}