#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(void) {
  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;
}
