#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, k, q, 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;
}