#!/usr/local/bin/perl
# day 2015-20

use strict;
use warnings;
use v5.32;
use Math::Prime::Util qw( divisors );
use List::Util        qw( sum );

my $input = 33100000;
my $house = 1;
$house++ while ( sum( divisors( $house ) ) * 10 < $input );
say "part 1: ", $house;

$house = 1;
do { $house++ } until 11 * sum(grep { $_ >= $house/50 } divisors($house)) >= $input;
say "part 2: ", $house;