#include <bits/stdc++.h>
 
#define dbg(x) cerr<<#x": "<<x<<"\n"
 
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
 
vector<int> v[100010], euler, nivel;
int rmq[20][200010],first[100010],l2[200010];
int x,n,m,y;
 
void dfs(int nod, int niv)
{
  first[nod] = euler.size();

  for (auto i : v[nod]) {
    euler.push_back(nod);
    nivel.push_back(niv);
    dfs(i, niv+1);
  }
  euler.push_back(nod);
  nivel.push_back(niv);

}
 
int LCA(int x, int y) {
  if(first[x] > first[y]) 
    swap(x, y);
  
  int l = l2[first[y]-first[x]+1];

  if (nivel[rmq[l][first[x]]] < nivel[rmq[l][first[y]-(1<<l)+1]])
    return euler[rmq[l][first[x]]];
  return euler[rmq[l][first[y]-(1<<l)+1]];
}

void pre() {
  for (int i=2;i<=2*n;i++)
    l2[i]=l2[i/2]+1;

  dfs(1,1);
  
  for (int i = 0;i < euler.size();i++)
    rmq[0][i] = i;
  
  for (int i = 1;(1<<i) < euler.size();i++)
    for (int j = 0; j + (1 << i)-1 < euler.size(); j++) 
      if (nivel[rmq[i-1][j]]<nivel[rmq[i-1][j+(1<<(i-1))]])
        rmq[i][j] = rmq[i - 1][j];
      else 
        rmq[i][j] = rmq[i - 1][j + (1 << (i - 1))];
}

int main()
{
  ios_base::sync_with_stdio(0);
  fin>>n>>m;
  for (int i=2;i<=n;i++) {
    fin>>x;
    v[x].push_back(i);
  }
  
  pre();

  for(int i = 1; i <= m; i++) {
    fin >> x >> y;
    fout << LCA(x, y) << '\n';
  }
}