Teacher Li led a class of students to plant trees. The students were divided into four groups on average, and a total of 667 trees were planted. If the teachers and students planted the same number of trees, how many students would there be in this class?
李老师带领一班学生去种树，学生恰好被平均分成四个小组，总共种树667棵，如果师生每人种的棵数一样多，那么这个班共有学生多少人．
<gadget id="calculator">29 - 1</gadget>
<output>28</output>

<result>28</result>