#include <stdio.h>

int A[1000000],n;

int binarysearch(int key){
  int left = 0;
  int right = n;
  int mid;
  while(left < right){
    mid = (left + right) / 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,q,k,sum = 0;

  scanf("%d",&n);
  for(i = 0;i < n;i++){
    scanf("%d",&A[i]);
  }

  scanf("%d",&q);
  for(i = 0;i < q;i++){
    scanf("%d",&k);
    if( binarysearch(k))
      sum++;
  }
  printf("%d\n",sum);

  return 0;
}

      

