There are four numbers, choose three of them each time, calculate their average, add another number, calculate four times in this way, and get the following four numbers respectively: 22, 25, 34, 39 , then what is the largest number among the original four numbers?
有四个数，每次选取其中三个数，算出它们的平均数，再加上另外的一个数，用这样的方法计算了四次，分别得到以下四个数：22、25、34、39，那么原来的四个数中最大的一个数是多少．
<gadget id="calculator">39 * 3</gadget>
<output>117</output>

<gadget id="calculator">117 - 60</gadget>
<output>57</output>

<gadget id="calculator">57 / 2</gadget>
<output>57/2 = around 28.5</output>

<result>57/2 = around 28.5</result>