#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 < A[mid]) 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;
}

