#include <stdio.h>

int A[1000000], n;

int binarySearch(int);

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;
}

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;
}

