Cut three knives along a straight line, and cut a rectangle with a length of 60 cm and a width of 30 cm into several small rectangles. What is the minimum sum of the perimeters of these small rectangles in cm?
沿直线剪三刀，将长为60厘米，宽30厘米的长方形剪成若干个小长方形，这些小长方形的周长之和最小是多少厘米．
<gadget id="calculator">2 * 60</gadget>
<output>120</output>

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

<gadget id="calculator">2 + 6</gadget>
<output>8</output>

<gadget id="calculator">8 * 30</gadget>
<output>240</output>

<gadget id="calculator">120 + 240</gadget>
<output>360</output>

<result>360</result>