On December 31, 2019, Lim has allowance for doubtful accounts of P4,000. Each month, Lim makes interim provision for bad debts equal to 1% of credit sales. During 2020, total credit sales are P1,000,000 and P16,000 of accounts receivable is written off. Aging of accounts receivable at December 31, 2020 indicates that an allowance of P20,000 should be provided for doubtful accounts as of that date. How much is the total amount of debit or total amount of credit in the adjusting entry (if there is any) to be made on December 31, 2020?