if($str =~ s/XLVIII$/IL/    or
                 $str =~ s/VIII$/IX/      or
                 $str =~ s/III$/IV/       or
                 $str =~ s/DCCCXCIX$/CM/  or
                 $str =~ s/CCCXCIX$/CD/   or

                 $str =~ s/LXXXIX$/XC/    or
                 $str =~ s/XXXIX$/XL/     or


                 $str =~ s/(I{1,2})$/$1I/ or

                 $str =~ s/CDXCIX$/D/     or
                 $str =~ s/CMXCIX$/M/     or
                 $str =~ s/XCIX$/C/       or

                 $str =~ s/I([VXLCDM])$/$1/ or
                 $str =~ s/([VXLCDM])$/$1I/) { }

              return $str;

##</code><code>##

              if($str !~ /[IVXLCDM]+/         ||
                 $str =~ /([IXC])\1{3,}/      ||
                 $str =~ /([VLD])\1{1,}/  ||

                 $str =~ /I[VXLCDM][IVXLCDM]/ ||
                 $str =~ /V[XLCDM][VXLCDM]/   ||
                 $str =~ /L[CDM][LCDM]/       ||
                 $str =~ /X[LCDM][XLCDM]/     ||
                 $str =~ /C[DM][CDM]/         ||
                 $str =~ /DM[DM]/) {
                  return 0;
              }

              return 1;