#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;
}