#include<stdio.h>
int A[10000],n;
int binarySearch(int key){
  int right = n;
  int left = 0;
  int mid;
  while(left<right){
    mid = (left + right) / 2;    
    if(A[mid] == key)return 1;
    else if(key<A[mid]){
      right = mid;
    }
    else if(key>A[mid]){
      left = mid + 1;
    }
  }
  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",sum);
  return 0;
}