The sum of the numerator and denominator of a simplest fraction is 23. After the numerator is increased by 5, the sum of the numerator and denominator of the simplest fraction obtained is 4. What is the original classification?
一个最简分数的分子与分母的和是23，分子增加5后，得到的最简分数的分子与分母的和是4，原来的分类是多少．
<gadget id="calculator">23 + 5</gadget>
<output>28</output>

<gadget id="calculator">28 / 4</gadget>
<output>7</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<gadget id="calculator">2 / 21</gadget>
<output>2/21 = around 0.095238</output>

<result>2/21 = around 0.095238</result>