A choir went to perform across a bridge at night, and they had only one flashlight. At most two people can cross the bridge together at one time, and there must be a flashlight when crossing the bridge, so someone has to bring the flashlight. When two people walk together, the slower speed prevails. The time for four people to cross the bridge is 1 minute, 2 minutes, 5 minutes, and 10 minutes respectively. How many minutes do they need at least?
某合唱团晚上经过一座桥去演出，他们只有一只手电筒．一次同时最多可以有两人一起过桥，而过桥的进候必须有手电筒，所以就得有人把手电筒带来带去，两人同行时以较慢者的速度为准．四人过桥的时间分别是1分、2分、5分、10分，他们最少需多少分．
<gadget id="calculator">2 + 1 + 10 + 2 + 2</gadget>
<output>17</output>

<result>17</result>