The Senior Citizens Association of Hongqi Village holds a meeting on the Double Ninth Festival. If 3 elderly people present at the meeting sit on one bench, then 5 people will have no seats; How many elderly people are there in the meeting?
红旗村老年协会在"重阳节"这天开会，到会的老年人，如果3人坐一长凳子，则5人没有座位；如果5人坐一长凳子，则刚好多一长凳子．问开会的老年人有多少人？
<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

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

<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<result>20</result>