#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 < mid[A]) 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;
}