Honghong's mother is very good at arranging time. She needs to do the following housework in the morning: 1. Clean the room for 8 minutes; 2. Boil water for 10 minutes; 3. Mop the floor for 5 minutes. What is the fastest time for him to finish these things?
红红的妈妈很善于安排时间，她早上需要做以下家务：1收拾房间8分钟；2烧水10分钟；3擦地5分钟．他做完这些事情最快需要多少分钟．
<gadget id="calculator">10 + 3</gadget>
<output>13</output>

<result>13</result>