#include <fstream>
#include <vector>
const int NMAX=200005;
const int LOG=17;

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

void dfs(int);
void init_lca();
bool is_ancestor(int, int);
int lca(int, int);

int dp[LOG+3][NMAX], in[NMAX], out[NMAX];
vector <int> v[NMAX];
int n, q, cnt;

int main()
{
  int i, a, b;
  fin>>n>>q;
  for(i=2; i<=n; i++)
  {
    fin>>dp[0][i];
    v[dp[0][i]].push_back(i);
  }
  dfs(1);
  init_lca();
  for(i=1; i<=q; i++)
  {
    fin>>a>>b;
    fout<<lca(a, b)<<'\n';
  }
}

int lca(int a, int b)
{
  int i;
  if(is_ancestor(a, b) || a==b) return a;
  if(is_ancestor(b, a)) return b;
  for(i=LOG; i>=0; i--)
  {
    if(!is_ancestor(dp[i][a], b) && dp[i][a]!=0)
    {
      a=dp[i][a];
    }
  }
  //am ajuns cu a la copilul lca-ului
  return dp[0][a];
}

bool is_ancestor(int a, int nod)
{
  return (in[a]<in[nod] && out[a]>out[nod]);
}

void init_lca()
{
  int i, j;
  for(j=1; j<=LOG; j++)
  {
    for(i=1; i<=n; i++)
    {
      dp[j][i]=dp[j-1][dp[j-1][i]];
    }
  }
}

void dfs(int nod)
{
  in[nod]=++cnt;
  for(auto i:v[nod])
  {
    if(!in[i]) dfs(i);
  }
  out[nod]=++cnt;
}