#include <fstream>
#include <vector>
#include <algorithm>
#include <math.h>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int n,m,ct,niv;
int h[100005];
int l[200005][21];
int e[200005][21];
vector <int>V[100005];

void DFS(int x)
{ ++ct;
   e[ct][0]=x;
   if(h[x]==0)
    h[x]=ct;
    l[ct][0]=niv;

   vector<int>::iterator it;
   for(it=V[x].begin();it!=V[x].end();++it)
          {  ++niv; DFS(*it);   --niv; ++ct; e[ct][0]=x; l[ct][0]=niv;    }

}


int main()
{  fin>>n>>m;
    int i,j,x,y,sol,z;
    for(i=1;i< n;++i)
    { fin>>x;
        V[x].push_back(i+1);
    }
    DFS(1);

  for(j=1;(1<<j)<=ct;++j)
    for(i=1;i+(1<<j)-1<=ct;++i)
        if( l[i][j-1]<l[i+(1<<(j-1))][j-1] )
  { l[i][j]=l[i][j-1];
     e[i][j]=e[i][j-1];
  }
  else { l[i][j]=l[i+(1<<(j-1))][j-1];
        e[i][j]=e[i+(1<<(j-1))][j-1];
  }
//fout<<h[5]<<" "<<h[11]<<"\n";
//for(i=1;i<=ct;++i)
   // fout<<l[i][0]<<" ";

  for(i=1;i<=m;++i)
  { fin>>x>>y;
      x=h[x]; y=h[y];
      if(x>y) swap(x,y);
      z=log2(y-x+1);
      if(l[x][z] <l[y-(1<<z)+1][z])
         sol=e[x][z];
      else sol=e[y-(1<<z)+1][z];
        fout<<sol<<"\n";
     // fout<<l[x][z]<<" "<<e[x][z]<<"\n";
     // fout<<l[y-z+1][z]<<" "<<e[y-z+1][z]<<"\n";
  }
    return 0;
}