There are 10 pieces of chocolate in a box, eat at least 1 piece every day, how many different ways to eat until you finish eating.
一盒巧克力有10块，每天至少吃1块，吃完为止，共有多少种不同的吃法．
<gadget id="calculator">2 ** 9</gadget>
<output>512</output>

<result>512</result>