#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;
}


