#include <iostream>
#include<cstdio>
#include<vector>
using namespace std;
const int N=100005;

int parceu[2*N];
int h[N];
int ap[N];
int rmq[2*N][20];
int poze=0;
vector <int> fi[N];

void screuler(int nod,int tata){
  h[nod]=1+h[tata];
  parceu[++poze]=nod;
  ap[nod]=poze;
  for(auto fiu : fi[nod]){
    screuler(fiu,nod);
    parceu[++poze]=nod;
  }
}

void makermq(){
  for(int i=1;i<=poze;i++)
    rmq[i][0]=parceu[i];
  for(int bit=1;bit<20;bit++){
    for(int i=1;i<=poze;i++){
      if(h[rmq[i][bit-1]] < h[rmq[min(i+(1<<(bit-1)),poze)][bit-1]] ){
        rmq[i][bit]=rmq[i][bit-1];
      }
      else{
        rmq[i][bit]=rmq[min(i+(1<<(bit-1)),poze)][bit-1];
      }
    }
  }
}

int qry(int x,int y){
  x=ap[x];
  y=ap[y];
  if(x>y)
    swap(x,y);
  int len=y-x+1;
  int p2=0;
  while((1<<p2)<=len)
    p2++;
  p2--;
  if(h[rmq[x][p2]] <= h[rmq[y-(1<<p2)+1][p2]])
    return rmq[x][p2];
  else
    return rmq[y-(1<<p2)+1][p2];
}
int main()
{
    FILE*fin,*fout;
    fin=fopen("lca.in","r");
    fout=fopen("lca.out","w");
    int n,m,x,y;
    fscanf(fin,"%d%d",&n,&m);
    for(int i=2;i<=n;i++){
      fscanf(fin,"%d",&x);
      fi[x].push_back(i);
    }
    screuler(1,0);
    makermq();
    for(int i=1;i<=m;i++){
      fscanf(fin,"%d%d",&x,&y);
      fprintf(fout,"%d\n",qry(x,y));
    }
    return 0;
}