#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;

}

