#include <stdio.h>
#define N 1000001                                                                            

int binarySearch(int A[], int n, int key)
{
  int left=0, right=n, 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, key, count=0;
  int n, A[N];

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

  scanf("%d", &q);

  for(i=0; i<q; i++){
    scanf("%d", &key);
    if(binarySearch(A, n, key)){
        count++;
      }
  }

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

  return 0;
}