#include<stdio.h>

#define N 1000000

int A[N],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;
}

