#include<stdio.h>
#define N 1000

int S[N],n,left,mid,right,key;
int BinarySearch();

int main(){
  int T[N],i,q,c=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",&T[i]);
  }
  for(i=0;i<q;i++){
    key=T[i];
    if(BinarySearch())c++;
    
  }
  printf("%d\n",c);
  return 0;
}
int BinarySearch(){
  left=0;
  right=n;
  while(left<right){
    mid=(left+right)/2;
    if(S[mid]==key)
      return 1;
    else if(key<S[mid])
      right=mid;
    else
      left=mid+1;
  }
  return 0;
}