A book has 200 pages in total. Pippi starts from page 1 and reads it in order from front to back. I read it on the first day (1/5), and read it on the second day (1/4). Which page do you start on the third day?
一本书共200页，皮皮从第1页开始，按从前往后的顺序看，第一天看了(1/5)，第二天看了(1/4)．第三天从哪一页看起？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(1/5) + (1/4)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">200 * (9/20)</gadget>
<output>90</output>

<gadget id="calculator">90 + 1</gadget>
<output>91</output>

<result>91</result>