Children's Day is coming soon, the school put up a square flower bed. There are 20 potted flowers on each side of the outermost layer of the flower bed, how many potted flowers are placed in the outermost layer.
六一儿童节快到了，学校摆放了一个方阵花坛．这个花坛最外层每边各放20盆花，最外层一共摆了多少盆花．
<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<gadget id="calculator">80 - 4</gadget>
<output>76</output>

<result>76</result>