my $filename = "C:/Users/jonas/OneDrive/Dokumente/PerlTutorial/Steckbriefe/Steckbrief_$count.txt"; do { say("$filename already exists!"); $count++; $filename = "C:/Users/jonas/OneDrive/Dokumente/PerlTutorial/Steckbriefe/Steckbrief_$count.txt"; } while (-e $filename);