#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;
  int 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;
}

