say for do {                    # <-- mixed paradigms --------
   my %seen;                    # <-- reinventing the wheel  |
   grep { not $seen{ $_ } ++ }  # <---------------------------                         
   map  { ( split m{;} )[ 1 ] } # too much logic, but that's nitpicking
   <$inFH>;
   };'

##</code><code>##

use List::Util qw(uniqstr);
say join "\n", 
   uniqstr
   map  { $_->[0] }
   map  { [ split m{;} ] }
   <$inFH>;