There are 5 students going to fetch water at the same time, and the time they need to fetch water is 5 minutes, 4 minutes, 3 minutes, 2 minutes, and 1 minute respectively. If there is only one faucet, what is the shortest time for them to line up and wait?
有5个同学同时去打水，他们打水所需要的时间分别是5分钟、4分钟、3分钟、2分钟、1分钟．若只有一个水龙头，要使他们排队和等候的时间最短，最短是多少分钟．
<gadget id="calculator">1 * 5</gadget>
<output>5</output>

<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">5 + 8 + 9 + 8 + 5</gadget>
<output>35</output>

<result>35</result>