#include<stdio.h>

int A[1000000],n;

int Search(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,j,k;
  int sum = 0;

  scanf("%d",&n);
  for(i=0;i < n; i ++){
    scanf("%d",&A[i]);
  }
  scanf("%d",&j);
  for(i=0; i < j; i++){
    scanf("%d",&k);
    if(Search(k)) sum++;
  }

  printf("%d\n",sum);

  return 0;
}

