#include<stdio.h>

int A[1000000],n;

int binarySearch(int key){
  int left=0;
  int right=n;
  int mid;
  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,k,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",&k);
    if(binarySearch(k)) sum++;
  }
  printf("%d\n",sum);
  
  return 0;
}

