#include<stdio.h>

int A[1000000],n;

int binarySearch(int);

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;
}


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<A[mid]) right=mid;
    }

  return 0;
}

