A simplest fraction ((a)/(b)) satisfies: (1/7)<((a)/(b))<(1/5), when the denominator is the smallest, a+b=how much.
一个最简分数((a)/(b))满足：(1/7)＜((a)/(b))＜(1/5)，当分母最小时，a+b=多少．
<gadget id="calculator">1 + 6</gadget>
<output>7</output>

<result>7</result>