Mingming told Xinxin that the product of three positive integers is 36, and at the same time told Xinxin the sum of these three numbers, but Xinxin still could not know exactly what the three numbers were. What is the sum of these three positive integers?
明明告诉欣欣有三个正整数的乘积为36，明明同时还告诉欣欣这三个数的和，但欣欣还是无法准确知道这三个数分别是什么．则这三个正整数之和为多少．
<gadget id="calculator">1 + 6 + 6</gadget>
<output>13</output>

<result>13</result>