#include <bits/stdc++.h>
#define dim 100005
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int prim[dim],nivel[dim],niv,euler[2*dim],k,Log[2*dim],d[30][2*dim],n,m,i,x,y;
vector<int> L[dim];
void e(int nod)
{
    euler[++k]=nod;
    prim[nod]=k;
    nivel[nod]=niv;
    for(auto it:L[nod])
    {
        niv++;
        e(it);
        niv--;
        euler[++k]=nod;
    }
}
int query(int st,int dr)
{
    int l=dr-st+1;
    int lg=Log[l];
    int p1=d[lg][st];
    int minn=k,sol;
    int p2=d[lg][st+l-(1<<lg)];
    if(nivel[p1]<nivel[p2])
        return p1;
    else
        return p2;
}
int main()
{
    fin>>n>>m;
    for(i=2; i<=n; i++)
    {
        int x;
        fin>>x;
        L[x].push_back(i);
    }

    e(1);

    /// RMQ
    for(i=1; i<=k; i++)
        d[0][i]=euler[i];
    int p=1;
    for(int lun=1; lun<=22; lun++)
    {

        ///
        for(i=1; i<=k-p+1; i++)
        {
            /// inceput secv
            int p1=d[lun-1][i];
            int p2=d[lun-1][i+p];
            if(nivel[p1]<nivel[p2])
            {
                d[lun][i]=p1;
            }
            else
                d[lun][i]=p2;
        }
         p*=2;
    }
    Log[1]=0;
    for(i=2; i<=k; i++)
        Log[i]=1+Log[i/2];

    for(i=1; i<=m; i++)
    {
        fin>>x>>y;
        x=prim[x];
        y=prim[y];
        if(x>y)
            swap(x,y);
        fout<<query(x,y)<<"\n";
    }
}