Use 2 yuan, 5 yuan, and 10 yuan each, and choose one or several of them, how many different moneys can be formed in total.
用2元、5元、10元的人民币各一张，选择其中的一张或几张，共可以组成多少种不同的钱数．
<gadget id="calculator">3 + 3 + 1</gadget>
<output>7</output>

<result>7</result>