Just fly 40 SAS flights(incl. Swedish domestic flight), then you'll be fine.

I travel to Sundsvall occassionally for work and gave up the flight from ARN as the train was much nicer (schedule was acutally better to). I am shuddering at the thought of domestic SK flights in economy

. Still negotiating my contract, and I will need to clarify how the company handles travel (compensation and booking class).