Xiaomei's habit of walking up the stairs is to only cross one or two steps each time. If she wants to walk from the ground (level 0) to level 9, ask her how many different ways of walking up the stairs?
小美步行上楼梯的习惯是每次都只跨一级或两级．若她要从地面(0级)步行到第9级，问她共有多少种不同的步行上楼梯的方式？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">5 + 8</gadget>
<output>13</output>

<gadget id="calculator">8 + 13</gadget>
<output>21</output>

<gadget id="calculator">13 + 21</gadget>
<output>34</output>

<gadget id="calculator">21 + 34</gadget>
<output>55</output>

<result>55</result>