#include<stdio.h>
#define N 10000

int binarySearch(int [], int, int [], int);

int main(){

  int n,m,i,j,a[N],b[N],c;

  scanf("%d",&n);
  
  for(i=0;i<n;i++){
    scanf("%d",&a[i]);
   
  
  }

  scanf("%d",&m);

  for(j=0;j<m;j++){
    scanf("%d",&b[j]);
  }
  c=binarySearch(a,n,b,m);

 printf("%d\n",c);
 return 0;
}

int binarySearch(int *S,int n,int *key,int m){
  int c=0;
  int left;
  int right;
  int mid,i;
 
 for(i=0;i<m;i++){
 left=0;
  right = n;
  while(left < right){
    mid = (left + right) / 2;
  
      if(S[mid]==key[i]){	
	c++;
	break;

      }
 
      else if(S[mid]>key[i]){
	right=mid;

	}
      
  
      
      else if(S[mid]<key[i]){
	left=mid+1;

      }
   
    }
  }
    
    
  return c;
}
 