Xiao Qiao reads a novel, if he reads 30 pages a day, he will read the complete book one day later than the scheduled date; if he reads 35 pages a day, he should read 5 pages less on the last day; if he reads 33 pages a day, how many pages should he read on the last day In order to finish reading this book by the stipulated date.
小巧读一本小说，如果每天读30页，则比规定的日期迟一天读完全书；如果每天读35页，则最后一天要少读5页；如果每天读33页，最后一天要读多少页才能按规定的日期读完这本书．
<gadget id="calculator">30 * 1</gadget>
<output>30</output>

<gadget id="calculator">30 + 5</gadget>
<output>35</output>

<gadget id="calculator">35 - 30</gadget>
<output>5</output>

<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<gadget id="calculator">35 * 7</gadget>
<output>245</output>

<gadget id="calculator">245 - 5</gadget>
<output>240</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">33 * 6</gadget>
<output>198</output>

<gadget id="calculator">240 - 198</gadget>
<output>42</output>

<result>42</result>