The students planted trees. The third grade planted 36 trees, the number of trees planted in the third grade was twice that of the fourth grade, and the number of trees planted in the fifth grade was 8 fewer than the total number of the third and fourth grades. How many trees did the fifth grade plant?
同学们种树，三年级种了36棵，三年级种的棵数是四年级的2倍，五年级种的棵数比三、四年级的总数少8棵．五年级种了多少棵？
<gadget id="calculator">36 / 2</gadget>
<output>18</output>

<gadget id="calculator">36 - 8</gadget>
<output>28</output>

<gadget id="calculator">18 + 28</gadget>
<output>46</output>

<result>46</result>