#include <stdio.h>
#include <stdlib.h>

#define K 1000000
int A[K],n;

int binarysearch(int key){
  int left = 0;
  int right = n;
  int mid;
  while(left< right){
  mid = (right+left)/2;
  if(key == A[mid]) return 1;
  if(key > A[mid]) left = mid +1;
  else if(key<A[mid]) right = mid;
  }
   return 0;
}





int main(){
 
  int i,M,L,count=0;
  
  scanf("%d",&n);
 
  for(i=0;i<n;i++)
  scanf(" %d",&A[i]);
  
  scanf("%d",&M);
  for(i=0;i<M;i++){
  scanf("%d",&L);
  if(binarysearch(L) )count++;
  }

  printf("%d\n",count);  
  



  return 0;
}

