#include<stdio.h>
int main(){
  int n,q,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",&q);
  for(i=0; i < q; i++){
    scanf("%d",&t[i]);
  }
 
  for(i = 0; i < q; i++){
    left = 0;
    right = n;
    while( left < right){
      mid = (left + right) / 2;
      if (s[mid] == t[i]){
	count++;
	break;
      }
      else if(t[i] < s[mid]){
	right = mid;
      }
      else {
	left = mid + 1;
      }
    }
  }
  printf("%d\n",count);
  return 0;
}