#include<stdio.h>

int Search(int key, int A[], int n)
{
  int left, right, mid;
  left = 0;
  right = n;
  while(left < right)
    {
      mid = (left + right) / 2;
      if(A[mid] == key)
	{
	  return 1;
	}
      else if(key < A[mid])
	{
	  right = mid;
	}
      else
	{
	  left = mid + 1;
	}
    }
  return 0;
}
int main()
{
  int n, i, S[10000], q, key, sum = 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", &key);
      if(Search(key, S, n))
	{
	  sum++;
	}
    }
  printf("%d\n", sum);
  return 0;
}

