A, B, and C go to the school infirmary to see a doctor at the same time. It takes 3 minutes for A to change the dressing, 30 minutes for B to get physical therapy, and 7 minutes for C to get an injection. How does the school doctor reasonably arrange the order of treatment so that the sum of the treatment and waiting time of the three teams is the least? What is the minimum time?
A、B、C三人同时到校医务室看病，A换药要3分钟，B理疗要30分钟，C打针要7分钟．校医怎样合理安排治疗顺序，使得三队治疗及等候时间的总和最少？最少的时间是多少？
<gadget id="calculator">3 + 3 + 3 + 7 + 7 + 30</gadget>
<output>53</output>

<result>53</result>