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

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

int n,m,tata[100005],levels[100005],var2[100005];
vector <int> V[100005];
const int h=320;

void DFS(int x,int anterior)
{
    var2[x]=anterior;
    if(levels[x]%h == 0) anterior = x;
    for(int i=0; i<V[x].size(); ++i)
    {
        levels[V[x][i]]=levels[x]+1;
        DFS(V[x][i],anterior);
    }
}

int main()
{
    f>>n>>m;
    for(int i=2; i<=n; ++i)
    {
        f>>tata[i];
        V[tata[i]].push_back(i);
    }
    levels[1]=0;
    DFS(1,0);
    for(int i=1; i<=m; ++i)
    {
        int x,y;
        f>>x>>y;
        while(var2[x]!=var2[y])
        {
            if(levels[x]>levels[y])
                x=var2[x];
            else
                y=var2[y];
        }
        while(x!=y)
        {
            if(levels[x]>levels[y])
                x=tata[x];
            else
                y=tata[y];
        }
        g<<x<<'\n';
    }
}