#include"stdio.h"
#include"stdlib.h"
struct num
{
  int n;
  struct num *next;
};
int binarySearch(int *A,int n,int key)
{
  int mid;
  int left=0;
  int right;
  right=n;
  while(left<right)
    {
      mid=(left+right)/2;
      if(key==A[mid])
        {
          return mid;
        }
      else if(A[mid]<key)
        {
          left=mid+1;
        }
      else if(key<A[mid])
        {
          right=mid;
        }
    }
  return -1;
}
int main()
{
  int i,j;
  int *S;
  int n;
  int m;
  struct num *T;
  struct num *p;
  int q;
  int C=0;
  T=(struct num*)malloc(sizeof(struct num));
  scanf("%d",&n);
  S=(int*)malloc(sizeof(int)*n);
  for(i=0;i<n;i++)
    {
      scanf("%d",&S[i]);
    }
  scanf("%d",&q);
  for(i=0;i<q;i++)
    {
      scanf("%d",&m);
      for(p=T;p->next!=NULL;p=p->next)
        {
          if(p->next->n==m)break;
        }
      if(p->next==NULL)
        {
          p->next=(struct num*)malloc(sizeof(struct num));
          p->next->n=m;
          p->next->next=NULL;
        }
    }
  for(p=T->next;p!=NULL;p=p->next)
    {
      if(binarySearch(S,n,p->n)!=-1)
        {
          C++;
        }
    }
  printf("%d\n",C);
  return 0;
}
