To visit the underwater world, 186 people went to the second grade, three times as many people went to the third grade, and 28 fewer people went to the fourth grade than the total number of the second and third grades. How many people went to the fourth grade?
到海底世界游览，二年级去了186人，三年级去的人数是二年级的3倍，四年级去的人数比二、三年级的总人数少28人，四年级去了多少人？
<gadget id="calculator">186 * 3</gadget>
<output>558</output>

<gadget id="calculator">186 - 28</gadget>
<output>158</output>

<gadget id="calculator">558 + 158</gadget>
<output>716</output>

<result>716</result>