#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;
   }
    
