I don't know on which side I am supposed to be.Why don't you by a card for one line for 3 months,it's not that expensive...but when I think for the "quality" of our transport  and taking i mind that you are 4 stops away from the school, it seems fair to me not to stamp your ticket...Anyway,I was thinking that the foreigners are very strict with the rules and they stick to them,but after spending more than a year or so,you are catching from our mentality.Strange!What do you think is the right thing to do and why?Do we really not have to stamps our tickets?