#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;
} 

