how to check how many elements in a set java

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
/*
check a set size by set.size()
*/

public class MainClass {
  public static void main(String[] a) {
    String elements[] = { "A", "B", "C", "D", "E" };
    Set set = new HashSet(Arrays.asList(elements));

    System.out.println(set.size());
  }
}