#include<stdio.h>

int A[10000],n;

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


int main(){
  int i,q,key,sum = 0;
  
  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(serch(key)) sum++;
  }
  
  printf("%d\n",sum);
  
  return 0;
}