#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;
}

