Xiao Ming, Xiao Liang, and Xiao Lan came to the teacher's office at the same time. The time for the teacher to talk to them was: Xiao Ming 4 minutes, Xiao Liang 2 minutes, and Xiao Lan 6 minutes. Arrange the order reasonably. The total waiting time of the three people should be at least how many minutes.
小明、小亮、小兰三人同时来到老师办公室，老师同他们谈话的时间分别是：小明4分钟、小亮2分钟、小兰6分钟，合理安排顺序，三人等候时间的总和最少要多少分钟．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">2 + 4</gadget>
<output>6</output>

<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<result>10</result>