#include <stdio.h>

int main()
{
  int n,s[10000],q,t[500],i,count=0,right,left,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 < n;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;
}