Two integers, whose product can be divisible by the sum, are called a pair of "good numbers", such as 70 and 30, so how many pairs of good numbers are there among the sixteen integers 1, 2, ..., 16.
两个整数，它们的积能被和整除，就称为一对"好数"，例如70与30，那么在1、2、…、16这十六个整数中，有好数多少对．
<gadget id="calculator">6 + 12</gadget>
<output>18</output>

<gadget id="calculator">12 / 18</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">6 * (2/3)</gadget>
<output>4</output>

<result>4</result>