import java.math.BigDecimal;

class Main
{
  public static void main (String[] args) throws java.lang.Exception
  {
     BigDecimal z = new BigDecimal("0.00");
     BigDecimal z2 = null;

     // Wrong
     System.out.println(z == new BigDecimal(0));
     System.out.println(z == BigDecimal.ZERO);

     // Wrong too!
     System.out.println(BigDecimal.ZERO.equals(z));
 
     // Correct
     System.out.println(z.signum() == 0);
  }
}