Parent Company issued 10-year, 15% bonds with a par value of $500,000 on January 1, 2020 for $470,000. Interest is paid semiannually on June 30 and December 31. On December 31, 2021, $400,000 of the par value bonds were purchased by Sub Company for $410,000. Sub Company is an 80% subsidiary of the Parent Company. Both companies use the straight-line method to amortize bond premiums and discounts. 

The total amount of constructive loss is ___________________________.