use strict;
use warnings;

sub is_pw_valid {
    local $_ = $_[0];

    return
          !(/[a-z]/ && /[A-Z]/)                     ? length >= 20 
        : !/\d/                                     ? length >= 16
        : !/[\x21-\x2F\x3A-\x40\x5B-\x60\x7B-\x7E]/ ? length >= 12
        :                                             length >=  8
    ;
}