#include <stdio.h>

int A[1000000],n;

int B_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;
    if(key < A[mid])right = mid;
  }
  return 0;
}

int main(){
  int i, q, key, 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", &key);
    if(B_search(key))sum++;
  }
  printf("%d\n", sum);
}

