#include<stdio.h>

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


int main(){
  int i,n,q,A[10000],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(A,n,key)) sum++;
  }

  printf("%d\n",sum);

  return 0;
}