#include<stdio.h>
 
int S[100000], n;
 
int binarySearch(int key){
  int left = 0;
  int right = n;
  int mid;
 
  while(left < right){
    mid = (left + right) / 2;
    if(key == S[mid]) return 1;
    if(key > S[mid]) left = mid+1;
    else if(key < S[mid]) right = mid;
  }
  return 0;
}
 
int main()
{
  int q, T[50000], C, i;
  C = 0;
  scanf("%d", &n);
  for(i = 0;i < n;i++) scanf("%d", &S[i]);
  scanf("%d", &q);
  for(i = 0;i < q;i++){
    scanf("%d", &T[i]);
    if(binarySearch(T[i])) C++;
  }
  printf("%d\n", C);
  return 0;
}