#include <stdio.h>
int S[100000],n;
int binarySearch(int);

int main(){
  int q,key,i,count=0;

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

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

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