As a member of the audit team responsible for the audit of Corpuz Company's for the year 2021, you were assigned to perform cut-off test for the beginning and ending inventory balances of the company to be able the Cost of goods sold and inventory reported in the financial statements. Assume that all purchases are FOB shipping point. In the course of your examination, the following facts were discovered:

December 31, 2020

a.) Invoice totaling P36,000 were entered in the voucher register in January, but the goods were received during December.

b.) December invoices totaling P32,000 were entered in the voucher register in December, but the goods were not received until January.

December 31, 2021

a.) Sales of P20,000 were made on account on December 31 and the goods were delivered at that time but the sale was recorded in January.

b.) Invoices totaling P24,000 for goods received in December were entered in the voucher register in January.

c.) December invoices totaling P8,000 were entered in the voucher register in December, but the goods were not received until January.

d.) Invoices totaling P4,000 were entered in the voucher register in January, and the goods were received in January. However, upon examination of these invoices, you determined that these are all shipped December.

Compute the net effect (overstated/understated) of the above errors on the following 2021 accounts:

1.) Retained earnings-prior period error

2.) Sales

3.) Ending inventory

4.) Accounts payable

5.) Cost of goods sold