It is necessary to build a rectangular pigsty with an area of 72 square meters. When the length is measured in meters, the sides of the rectangle are all natural numbers. What is the minimum total length of the walls of this pigsty in meters?
要砌一个面积是72平方米的长方形猪圈，当以米为长度单位时，长方形的边长都是自然数，这个猪圈的围墙总长最少是多少米．
<gadget id="calculator">8 + 9</gadget>
<output>17</output>

<gadget id="calculator">17 * 2</gadget>
<output>34</output>

<result>34</result>