You can do solve the problem without the "lines" variable but, believe me, you want to keep those lines in a collection. It's gonna be a lot easier down the road! Hint (to solve the problem) : look at what "lines" contain (instances of which class). That class has everything you need to parse those '+2' and '-8' ... ;) | file | lines := OrderedCollection new. file := StandardFileStream readOnlyFileNamed: 'day.1.input'. [file atEnd] whileFalse: [lines add: file nextLine]. file close. ----------------- Benoît St-Jean Yahoo! Messenger: bstjean Twitter: @BenLeChialeux Pinterest: benoitstjean Instagram: Chef_Benito IRC: lamneth Blogue: endormitoire.wordpress.com "A standpoint is an intellectual horizon of radius zero". (A. Einstein) On Sunday, December 2, 2018, 6:09:42 a.m. EST, Roelof Wobben <r.wobben@home.nl> wrote: Op 2-12-2018 om 11:55 schreef Benoit St-Jean via Pharo-users: Nope, only the part how I can read the file. Roelof