AoC 2022, day 25 (Perl)

#!/usr/bin/perl

use strict;
use warnings;

my %val = ( '=' => -2, '-' => -1, 0 => 0, 1 => 1, 2 => 2 );
my %mod = ( 0 => 0, 1 => 1, 2 => 2, 3 => '=', 4 => '-' );

my $sum = 0;
while (<>) {
    chomp;

    my $pow = 1;
    my $num = 0;
    foreach my $dig (reverse split //) {
        $num += $val{$dig} * $pow;
        $pow *= 5;
    }

    $sum += $num;
}

print "Sum: $sum\n";

my @part1;
while ($sum) {
    my $dig = $sum % 5;
    unshift( @part1, $mod{$dig} );
    $sum = int( $sum / 5 ) + ($dig >= 3);
}

print "Part 1: ", @part1, "\n";