#include<stdio.h>
int A[1000000],n;
int binarySearch(int key){
  int left = 0, right = n, mid;
  while(left < right){
    mid = (left + right)/2;
    if(key == A[mid]) return 1;
    else if(key > A[mid]) left = mid + 1;
    else right = mid;
  }
  return 0;
}
int main(){
  int i,q,num,C = 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",&num);
    if(binarySearch(num))C++;
  }
  printf("%d\n",C);
  
  return 0;
}

