If a multi-digit number increases sequentially from left to right, it is called an ascending number, such as 1357, 256, etc. How many rises are there?
如果一个多位数的数字从左到右是依次增大的，就称这个数是上升数，如1357、256等．上升数共有多少个？
<gadget id="calculator">2 ** 9</gadget>
<output>512</output>

<gadget id="calculator">512 - 1 - 9</gadget>
<output>502</output>

<result>502</result>