The four numbers A, B, C, and D, remove one number at a time, find the average of the remaining three numbers, and get the following four numbers, 23, 26, 30, 33, then A, B, C, and D What is the average number of numbers?
A、B、C、D四个数，每次去掉一个数，求出其余三个数的平均数，得到下面四个数，23，26，30，33，那A、B、C、D四个数的平均数是多少？
<gadget id="calculator">23 + 26 + 30 + 33</gadget>
<output>112</output>

<gadget id="calculator">112 / 4</gadget>
<output>28</output>

<result>28</result>