If you buy the tickets in sections at the time of ticket purchase, the number of rides will be cancelled directly at the time of ticket purchase. If the segmented tickets are purchased separately, if you can show the purchase certificate of the first segment ticket when purchasing the second segment ticket, the second segment ticket will not be multiplied, otherwise it will be multiplied twice.
Student tickets are not purchased at regular intervals. Sometimes, you can buy tickets beyond arrival, departure or arrival. However, the part beyond the scope can not enjoy the student fare discount, and can only make up the full fare difference.
Matters needing attention
If the student ticket you bought is not in the preferential area, you can't pass the gate by swiping your card into the station. However, the staff will generally ask you to refund the ticket before buying the ticket, but a small number of staff will let you directly make up the difference.
If you are asked to refund the ticket when you enter the station, 20% of the fare will be charged as a refund fee. Even if you are accidentally put on the train, the flight attendant will check the ticket on the train and still need to make up the difference after being discovered by the flight attendant.