$12.$

A company uses a periodic inventory system. Beginning inventory on January $1$ was understated by $$30,300,$ and its ending inventory on December $31$ was understated by $$15,100.$ In addition, a purchase of merchandise costing $$21,300$ was incorrectly recorded as a $$2,130$ purchase. None of these errors were discovered until the next year. As a result, cost of goods sold for the current year was: