Xiaohong's room needs to be repainted. One of the rectangular walls is 5 meters long and 3 meters wide. This wall has a square window with a side length of 2 meters. Please help Xiaohong calculate how big the wall in her room needs to be painted?
小红的房间要重新粉刷．其中有一面长方形墙壁长5米，宽3米．这面墙壁有一扇正方形窗户，边长是2米．请你帮助小红算算，她房间的这面墙壁要粉刷的有多大？
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">15 - 4</gadget>
<output>11</output>

<result>11</result>