A room is 6 meters long, 5 meters wide, and 3 meters high. It is necessary to paint green paint with a height of 1 meter on the four walls of the room (the door is 1 square meter without painting), how many square meters is the painted area?
一个房间长6米，宽5米，高3米，要在房间的四面墙壁涂1米高的绿色油漆(门1平方米不刷)，涂油漆的面积是多少平方米？
<gadget id="calculator">6 * 1 * 2</gadget>
<output>12</output>

<gadget id="calculator">5 * 1 * 2</gadget>
<output>10</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">12 + 9</gadget>
<output>21</output>

<result>21</result>