A train departs from Fuzhou to Yong'an, and stops at Nanping, Laizhou, Shaxian, and Sanming along the way. How many different tickets should the railway department prepare for this train?
一列火车从福州开往永安，沿途停靠南平、来舟、沙县、三明4个站，铁路部门要为这辆列车准备多少种不同的车票．
<gadget id="calculator">5 + 4 + 3 + 2 + 1</gadget>
<output>15</output>

<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<result>30</result>