#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;
      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;
}