#include<stdio.h>

int S[100000], n;

int binarySearch(int key){

  int left = 0;
  int right = n;
  int mid;

  while ( left < right ) {
    mid = (left + right) / 2;
    if ( S[mid] == key ) return 1;
    else if ( key < S[mid] ) right = mid;
    else left = mid + 1;
  }
  return 0;
}

int main(){

  int q, i, t, count;
  sum = 0;

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

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

  return 0;

}