There are 5 small stations on a certain train from A to B, how many different fares are there for this train?
从A地到B地的某次列车，途中有5个小站，这次列车有多少种不同的票价．
<gadget id="calculator">6 + 5 + 4 + 3 + 2 + 1</gadget>
<output>21</output>

<gadget id="calculator">21 * 2</gadget>
<output>42</output>

<result>42</result>