Xiaoming's study is 4 meters long, 3 meters wide, and 3 meters high. Excluding the doors and windows, it is 4.5 square meters. It needs to be painted around. How many square meters is the area to be painted?
小明的书房长4米，宽3米，高3米，除去门窗4.5平方米，要给四周涂上涂料，刷涂料的面积是多少平方米？
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

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

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<gadget id="calculator">42 - 4.5</gadget>
<output>37.5</output>

<result>37.5</result>