book has 54 pages in total. Those who read this book on the first day (1/6), and those who read this book on the second day (2/9), how many pages are left unread?
一本书共54页，第一天看这本书的(1/6)，第二天看这本书的(2/9)，还剩多少页没有看？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 - (1/6) - (2/9)</gadget>
<output>11/18 = around 0.611111</output>

<gadget id="calculator">54 * (11/18)</gadget>
<output>33</output>

<result>33</result>