#include<stdio.h>
#define N 100001

int binarysearch(int * ,int ,int);

int main (){
  int n,i,S[N],q,key,num=0;
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&S[i]);
  }
  scanf("%d",&q);
  for(i=0;i<q;i++){
    scanf("%d",&key);
    //if(linersearch(S,n,key)!=0)
    num=num+binarysearch(S,n,key);
  }
  printf("%d\n",num);
 
  return 0;
}

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

