In order to celebrate the National Day, a total of 500 colored flags were planted on the railing of the Runyang Bridge from beginning to end, and a potted flower was placed in the middle of every two colored flags. How many potted flowers are needed in total.
为了庆祝国庆节，在润扬大桥的栏杆上插彩旗，从头到尾共插500面，每两面彩旗中间放一盆花，一共需要多少盆花．
<gadget id="calculator">500 - 1</gadget>
<output>499</output>

<gadget id="calculator">499 * 1</gadget>
<output>499</output>

<result>499</result>