#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];
int nivel[200010],euler[200010],i,j;
int rmq[20][200010],first[100010],l2[200010];

void dfs(int nod, int niv)
{
  first[nod]=euler[0]+1;
  for (auto i:v[nod])
  {
    euler[++euler[0]]=nod;
    nivel[++nivel[0]]=niv;
    dfs(i,niv+1);
  }
  euler[++euler[0]]=nod;
  nivel[++nivel[0]]=niv;
}

int main()
{
  int x,i,n,m,y;
  fin>>n>>m;
  for (i=2;i<=2*n;i++)
  {
    l2[i]=l2[i/2]+1;
  }
  for (i=2;i<=n;i++)
    {
      fin>>x;
      v[x].push_back(i);
    }
  dfs(1,1);
  for (i=1;i<=euler[0];i++)
    rmq[0][i]=i;
  for (i=1;(1<<i)<=euler[0];i++)
  {
    for (j=1;j+(1<<i)-1<=euler[0];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))];
    }
  }
  for (i=1;i<=m;i++)
  {
    fin>>x>>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]])
      fout<<euler[rmq[l][first[x]]]<<'\n';
    else fout<<euler[rmq[l][first[y]-(1<<l)+1]]<<'\n';
  }
}