#include<stdio.h>


int main(){

 int a[100000],b[50000],n,m,i,j;
 int count=0;
 int left,mid,right;

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

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


    for(i=0;i<n;i++){
       left=0;
       right=n;
       mid=(left+right)/2;
      if(a[mid]==b[i]){count++;
       break;
       }
      else if(a[mid] < b[i]){
      left=mid + 1;}
   else{
        right=mid-1;
      }
 }
 printf("%d\n",count);
 return 0;
}