Little A, little B, little C and little D four people cross the bridge, each need 2 minutes. , 3 minutes, 5 minutes, 10 minutes, because it was dark, they had to use a flashlight to cross the bridge, but they had 1 flashlight in total, and the load capacity of the bridge was limited. 2 people are now required to cross the bridge in the shortest time, how can the shortest time be achieved? Please come and arrange for them. How many minutes is the shortest time?
小A、小B、小C和小D四人过桥，分别需要2分钟．、3分钟、5分钟、10分钟，因为天黑，必须借助手电筒过桥，可是他们共有1个手电筒，并且桥的载重量有限，最多只能承受2个人的重量，也就是说每次最多过2个人，现在要求用最短的时间过桥，怎样才能做到时间最短呢？请你来帮他们安排一下，看最短时间是多少分钟？
<gadget id="calculator">3 + 2 + 10 + 3 + 3</gadget>
<output>21</output>

<result>21</result>