Xiao Zhang, Xiao Li and Xiao Wang went to see a doctor at the same time. Xiao Zhang needs 3 minutes, Xiao Li needs 5 minutes, and Xiao Wang needs 2 minutes. In order to minimize the total waiting time of the three of them, what order should they see the doctor in? How long is the minimum waiting time?
小张、小李和小王同时去看病．小张需要3分钟，小李需要5分钟，小王需要2分钟．要使他们三人的等候时间总和最少，应该按照怎样的顺序看病？最少等多少时间？
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

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

<gadget id="calculator">6 + 6 + 5</gadget>
<output>17</output>

<result>17</result>