use strict;
use warnings;

my $max=0;
my %val=map { $_ => $max++ } split //,'MDCLXVI';


sub rtol {
    my ($word)=@_;

    my @r = (".") x $max;
    my $last = $max + 1;

    while (length $word) {
        my $c=chop $word;
        if ($val{$c}<$last) {
            $r[$val{$c}]=$c;
            $last=$val{$c};
        }
    }
    return join "",@r;
}

sub ltor {
    my ($word)=@_;

    my @r = (".") x $max;
    my $last = -1;

    for my $c (split //,$word) {
        if ($val{$c}>$last) {
            $r[$val{$c}]=$c;
            $last=$val{$c};
        }
    }
    return join "",@r;
}

printf "%7s => %7s  ( %7s : %-3s) ( %7s : %-3s )\n", qw(Input Expect LtoR ok? RroL ok?);
printf "%7s    %7s    %7s   %-3s    %7s   %-3s  \n", ("---") x 6;
while(<DATA>) {
    last unless /\S/;
    chomp;
    my ($input,$expect)=split /\s+/,$_;
    my $ltor=ltor($input);
    my $rtol=rtol($input);

    printf "%7s => %7s  ( %7s : %-3s) ( %7s : %-3s )\n",
        $input, $expect,
        $ltor, $ltor eq $expect ? 'Ok' : 'Not',
        $rtol, $rtol eq $expect ? 'Ok' : 'Not';

}


__END__
I              ......I
IV             .....V.
V              .....V.
VI             .....VI
IX             ....X..
X              ....X..
XI             ....X.I
XIV            ....XV.
XV             ....XV.
XVI            ....XVI
XIX            ....X.I
X              ....X..
XL             ....X..
LX             ...LX..
XC             ....X..
CLXIX          ..CLX.I
CDXLVI         .D..XVI
MCMXCVI        M.C.XVI
MDCLI          MDCL..I