# assign valid strings
my @valid = (
  '$1',
  '$1.11',
  '$.11',
  '-$1',
  '-$1.11',
  '-$.11',
  '$-1',
  '$-1.11',
  '$-.11',
);

##</code><code>##

# assign valid strings
my @valid = qw(
   $1
   $1.11
   $.11
  -$1
  -$1.11
  -$.11
   $-1
   $-1.11
   $-.11
);