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

  int i,j,n,q,S[10001],T[501];

  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[i] );
  }

  int key,cnt;
  cnt = 0;

  for ( i = 0; i < q; i++ ){
    key = T[i];
    for ( j = 0; j < n; j++ ){
      if ( S[j] == key ){
	cnt += 1;
	break;
      } 
    }
  }

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

  return 0;

}