#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;
}
