#include<stdio.h>

int A[10000],n;

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

int main(void){
  int i,q,num,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",&num);
    if(binarySearch(num)) sum++;
  }
  printf("%d\n",sum);
}