#include<stdio.h>

int main(){

  int n,m,s[10000],t[500],i,j,count = 0,left,right,mid;

  scanf("%d",&n);

  for(i = 0; i < n ;i++){

    scanf("%d",&s[i]);
  }

  scanf("%d",&m);

  for(i = 0; i < m ; i++){

    scanf("%d",&t[i]);
  }


  
  for(i = 0 ; i < m; i++){
  left = 0;
  right = n;

    while(left < right){
    	mid = (left+right)/2;
      
      if(s[mid] == t[i]){

	count++;
	break;
      }

      else if(s[mid] > t[i]){
	right = mid;
	
      }

      else{
	left = mid+1;
	
      }
    }

  

  }

  printf("%d\n",count);

  return 0;
}
	

