#include <stdio.h>
int main(void){

  int n, q, i, left, right, mid;
  int m = 0;

  scanf("%d", &n);

  int S[n];

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

  scanf("%d", &q);

  int T[q];

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


  for(i = 0; i < q; i++) {
  left = 0;
  right = n;
  while(left < right){
    mid = (left + right) / 2;
      if (S[mid] == T[i]){
        m++;
        break;
        }
   else if (T[i] < S[mid]){
     right = mid;
        }
    else {
      left = mid + 1;
        }
   }

   }

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

   return 0;

}
