Embroider flowers around the square towel, one at each of the four vertices, so there are 5 flowers on each side. How many flowers are there around the towel?
在正方形毛巾四周绣花，四个顶点各绣一朵，这样每边都有5朵．毛巾四周一共有多少朵花．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<result>16</result>