#include<stdio.h>

int binarySearch(int a[],int key){
  left = 0;
  right = n;
  while(left < right){
    mid =(leht+right)/2;
    if(a[mid]== key)
    return a;
    else if(key < a[mid])
      right=mid;
      else
      left=mid+1;


  }
  return 0;


}

int main(){
  int i,n,q,key,sum=0;
  int a[100000];
  scanf("%d",&n);
  for(i=0;i<n,i++){
    scanf("%d",&a[i]);
  }

  scanf("%d",&q);
  for(i=0;i<q;i++){
    scanf("%d",&key);
    if( binarySearch(a,key)) sum++;
  }
  printf("%d\n",sum);

  return 0;
}

