#include<stdio.h>
int A[10000000], 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;
}
