use strict;
use warnings;

print "Starting\n";
for (1 .. 100000) {
    my @results = draw();
    
    print "@results\n" if 2 != @results;
}
print "Done\n";


sub draw {
    my @dic = ('thew', 'trow', 'whew');
    my %master_letter_freq;
    my $master_letter_list = 'otrwreh';
    my $regex              = '';

    ++$master_letter_freq{$_} for split //, $master_letter_list;

    for (split //, '---w') {
        $regex .= $_ eq '-' ? "[$master_letter_list]" : $_;
    }

    my @result = grep {/^$regex$/i} @dic;
    my @results;

RESULT: foreach (@result) {
        my %seen;
        $seen{$_}++ for (split //, lc $_);

        foreach (keys %seen) {
            next RESULT if ($seen{$_} > $master_letter_freq{$_});
        }

        push @results, $_;
    }

    return @results;
}