To place flower pots on the edge of the pentagonal pool so that there are 4 potted flowers on each side, how can it be placed?
要在五边形的水池边上摆上花盆，使每一边都有4盆花，可以怎样摆放？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>