My sister reads a book. She reads 25% of the whole book in the first week, and 34% of the whole book in the second week. She reads 18 pages less in the first week than in the second week. How many pages does the book have?
姐姐看一本书，第一周看了全书的25%，第二周看了全书的34%，第一周比第二周少看了18页，这本书一共有多少页？
<gadget id="calculator">34 / 100</gadget>
<output>17/50 = around 0.34</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(17/50) - (1/4)</gadget>
<output>9/100 = around 0.09</output>

<gadget id="calculator">18 / (9/100)</gadget>
<output>200</output>

<result>200</result>