Can you please tell me how to get the answer? I know what it is, but I don't understand how to arrive at the final answer

Oasis, Inc. has common shares with a price of $21.12 per share. The firm is expected to pay a dividend of $1.75 one year from today, and dividends are expected to grow at 10 percent for two years after that and then at 5 percent thereafter. What is the implied cost of common equity capital for Oasis?