The Smithson Corporation acquired all of the outstanding common stock of the Rider Corporation in exchange for $180 million cash. Smithson assumed all of Riders long-term liabilities, which have a fair value of $120 million at the date of acquisition. The fair values of all identifiable assets of Rider are as follows: receivables of $50 million, inventory of $70 million, property, plant, and equipment of $90 million, and patent of $40 million). What is the cost of the goodwill resulting from the acquisition?