#include <fstream>
#include <vector>
#include <cmath>
#include <algorithm>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int n,x,y,m;
const int N=1e5+50;
vector<int>a[N];
int euler[3*N];
int poz[N],nr,X,Y,niv[N];
int rmq[20][2*N];
void dfs(int nod,int tt)
{
    euler[++nr]=nod;
    poz[nod]=nr;
    niv[nod]=niv[tt]+1;
    for(auto x : a[nod])
    {
        if(tt==x)
            continue;
        dfs(x,nod);
        euler[++nr]=nod;
    }
}
bool compare(int X,int Y)
{
    return niv[X]<niv[Y];
}
int main()
{
    f>>n>>m;
    for(int i=2;i<=n;i++)
    {
        f>>X;
        a[X].push_back(i);
        a[i].push_back(X);
    }
    dfs(1,0);
    for(int i=1;i<=nr;i++)
        rmq[0][i]=euler[i];
    for(int j=1;(1<<j)<=nr;j++)
    {
        int dr=(1<<j);
        for(int i=1;i<=nr-dr;i++)
            rmq[j][i]=min(rmq[j-1][i],rmq[j-1][i+dr/2],compare);
    }
    for(int i=1;i<=m;i++)
    {
        f>>x>>y;
        int lft=poz[x];
        int rgt=poz[y];
        if(lft>rgt)
            swap(lft,rgt);
        int lg=log2(rgt-lft+1);
        g<<min(rmq[lg][lft],rmq[lg][rgt-(1<<lg)+1],compare)<<'\n';
    }
    return 0;
}