my $winner = $1 if $R =~ /(\[[^#]*(?:\]|#[^#]*\]))/;

##</code><code>##

my $winner = $1 if $R =~ /(\[[^#]*(?:#[^#]*)?\])/; 

##</code><code>##

/(              # Start capturing.
    \[          # A literal left bracket.
    [^#]*       # Anthing that is not an octothorp
    (?:           # Group without capturing
       \#         # A literal octothorp
       [^#]*      # Anything that is not an octothorp
    )?            # End group. Group is optional.
    \]          # literal right bracket.
)/x