Please find the ending inventory at cost with the LIFO retail method. I calculated $21,816 which is being marked as wrong, and I don't understand why. Thank you so much!

Monty Company began operations late in 2019 and adopted the conventional retail inventory method. Because there was no beginning inventory for 2019 and no markdowns during 2019, the ending inventory for 2019 was $14,066 under both the conventional retail method and the LIFO retail method. At the end of 2020, management wants to compare the results of applying the conventional and LIFO retail methods. There was no change in the price level during 2020. The following data are available for computations. Cost Retail Inventory, January 1, 2020 $14,066 $18,600 Sales revenue 73,000 Net markups 9,900 Net markdowns 1,600 Purchases 62,900 76,200 Freight-in 4,700 Estimated theft 1,900