AoC 2021 day 24, Perl exploration

#!/usr/bin/perl

use strict;
use warnings;

use List::AllUtils  qw(indexes pairwise);

my @Code = map { chomp; $_ } <>;
my @Blocks = indexes { $_ =~ m#inp# } @Code;

my @Fixed = @Code[0 .. 17];

foreach my $bi (@Blocks) {
    foreach my $l (0 .. 17) {
        if ($Code[$bi + $l] ne $Fixed[$l]) {
            $Fixed[$l] = join( ' ', pairwise { ($a eq $b) ? $a : '???' }
                                        @{[split(/ /, $Fixed[$l])]},
                                        @{[split(/ /, $Code[$bi + $l])]});
        }
    }
}

print join( "\n", @Fixed );