The train between Shanghai and Nanjing has to stop at 26 stations in addition to the starting point and the ending point. How many kinds of tickets should the railway department prepare?
上海与南京之间的火车，除起点、终点外，还要停靠26个站，铁路部门要准备多少种车票．
<gadget id="calculator">27 + 26 + 25 + 24 + 23 + 22 + 21 + 20 + 19 + 18 + 17 + 16 + 15 + 14 + 13 + 12 + 11 + 10 + 9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1</gadget>
<output>378</output>

<gadget id="calculator">378 * 2</gadget>
<output>756</output>

<result>756</result>