#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <bitset>

using namespace std;

ifstream in("lca.in");
ofstream out("lca.out");
const int NMAX = 100001;
int father[NMAX+1];
queue<int> coada;
vector<int> muchii[NMAX];
int n,m;
bitset<NMAX> mark;
int high[NMAX];

void citire()
{
  in>>n>>m;
  for(int i=1;i<n;i++)
   {
     in>>father[i+1];
     muchii[father[i+1]].push_back(i+1);
   }
}

void bfs()
{
  mark.set(1);
  coada.push(1);
  int y;
  while(!coada.empty())
  {
     y = coada.front();
     for(unsigned int i=0;i<muchii[y].size();i++)
       if(!mark.test(muchii[y][i]))
       {
        high[muchii[y][i]] = high[y] + 1;
        mark.set(muchii[y][i]);
        coada.push(muchii[y][i]);
       }
      coada.pop();
  }
}

int main()
{
    citire();
    bfs();
    int x,y;
    for(int i=1;i<=m;i++)
    {
      in>>x>>y;
      if(high[x] > high[y])
      {
         while(high[x] != high[y])
          x = father[x];
      }
      else
       if(high[y] > high[x])
       {
         while(high[y] != high[x])
          y = father[y];
       }
       while(x!=y)
       {
          x = father[x];
          y = father[y];
       }
       out<<x<<"\n";
    }
    in.close();
    out.close();
    return 0;
}