AoC day 14 (pt1), Perl

#!/usr/bin/perl

use strict;
use warnings;
no warnings qw(portable);

use List::AllUtils  qw(sum);

my %mem;
my $and_mask;
my $or_mask;

while (<>) {
    if (m#mask = ([10X]+)#) {
        $or_mask  = eval( "0b" . ($1 =~ y/X/0/r) );
        $and_mask = eval( "0b" . ($1 =~ y/X/1/r) );
    } elsif (m#mem\[(\d+)\] = (\d+)#) {
        $mem{$1} = ($2 | $or_mask) & $and_mask;
    }
}

print "Part 1: ", sum( values %mem ), "\n";