#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;
}

