#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;
}
  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;
}