#include <stdio.h>

int A[100000], n;

int binarySearch(int key)  {
  int left = 0, right = n, 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(void)  {
  int i, j, 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) != 0)
      sum++;
  }
  printf("%d\n", sum);

  return 0;
}
  