Mingming's room is 4.5 meters long, 4 meters wide and 3 meters high. To paint the ceiling and four walls of the room, remove 4.5 square meters of doors and windows, and an average of 0.2 kilograms of lime per square meter. How many kilograms of lime are needed in total?
铭铭的房间长4.5米，宽4米，高3米．要粉刷房间的天花板和四面墙，除去门窗4.5平方米，平均每平方米的石灰0.2千克．一共需要石灰多少千克？
<gadget id="calculator">4.5 * 3</gadget>
<output>13.5</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">13.5 + 12</gadget>
<output>25.5</output>

<gadget id="calculator">25.5 * 2</gadget>
<output>51</output>

<gadget id="calculator">4.5 * 4</gadget>
<output>18</output>

<gadget id="calculator">18 - 4.5</gadget>
<output>13.5</output>

<gadget id="calculator">51 + 13.5</gadget>
<output>64.5</output>

<gadget id="calculator">64.5 * 0.2</gadget>
<output>12.9</output>

<result>12.9</result>