Two books, A and B, share 777 numbers on the pages, and book A has 7 more pages than book B. So, how many pages does Book A have?
甲、乙两册书，书页共用了777个数码，甲册比乙册多7页．那么，甲册书有多少页．
<gadget id="calculator">2 * 90</gadget>
<output>180</output>

<gadget id="calculator">777 - 9 - 180</gadget>
<output>588</output>

<gadget id="calculator">588 / 3</gadget>
<output>196</output>

<gadget id="calculator">100 - 1</gadget>
<output>99</output>

<gadget id="calculator">196 + 99</gadget>
<output>295</output>

<gadget id="calculator">295 + 7</gadget>
<output>302</output>

<gadget id="calculator">302 / 2</gadget>
<output>151</output>

<result>151</result>