#include <bits/stdc++.h>
using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

int n,m;
vector <int> V[100005];
int levels[100005],sqr[100005],tata[100005];
const int sqrH=320;


void DFS(int nod, int adancime)
{
    sqr[nod]=adancime;
    if(levels[nod]%sqrH == 0) adancime=nod;
    for(auto &it:V[nod])
    {
        levels[it]=levels[nod]+1;
        DFS(it,adancime);
    }
}

int main()
{
    f>>n>>m;
    for(int i=2; i<=n; ++i)
    {
        f>>tata[i];
        V[tata[i]].push_back(i);
    }
    levels[1]=1;
    DFS(1,0);
    while(m)
    {
        m--;
        int x,y;
        f>>x>>y;
        while(sqr[x]!=sqr[y])
        {
            if(levels[x]>levels[y])
                x=sqr[x];
            else
                y=sqr[y];
        }
        while(x!=y)
        {
            if(levels[x]>levels[y])
                x=tata[x];
            else
                y=tata[y];
        }
        g<<x<<'\n';
    }
    return 0;
}