#include <stdio.h>

int A[1000000], n;

int BinarySearch(int);

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;
}

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;
}

