#include<stdio.h>

int A[100000],n;

int binarySearch(int key){
  int left =0,right = n,mid;

  while(left < right){
    mid = (left+right)/2;
    if(A[mid]==key){
      return mid;
    }
    else if(key<A[mid]){
      right = mid;
    }
    else
      left=mid+1;
  }

  return -1;
}

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(binarySearch(key)!=-1){
      sum++;
    }
  }
  printf("%d\n",sum);

  return 0;
}
    

