Plant trees around a square playground, one of each kind in the four corners, and 12 trees are planted on each side, how many trees are planted in total on the four sides?
在一个正方形的操场四周种树，四角各种一棵，每边都种12棵，四边一共种树多少棵．
<gadget id="calculator">12 * 4</gadget>
<output>48</output>

<gadget id="calculator">48 - 4</gadget>
<output>44</output>

<result>44</result>