#include <stdio.h>

int A[1000000], n;

int binary(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, a=0, k;

  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(binary(k)) a++;
  }
  printf("%d\n", a);

  return 0;
}

