A simplest fraction ((a)/(b)) satisfies (1/7)<((a)/(b))<(1/6), when the denominator b is the smallest, find the value of a+b.
一个最简分数((a)/(b))，满足(1/7)＜((a)/(b))＜(1/6)，当分母b最小时求a+b的值．
<gadget id="calculator">2 + 13</gadget>
<output>15</output>

<result>15</result>