// this is a txt file because Splash won't let me upload a .java 
// file so rename it  --  jaz

import java.util.*;
import java.text.*;

class Pair {
    public final String fst;
    public final String snd;
    public Pair( String first, String second ) {
       fst = first; snd = second;
    }
}

class Lst extends LinkedList<Pair> {

   public Lst pr( String first, String second ) {
      add( new Pair(first, second) );
      return this;
   }

}  

public class RomanNum extends Number {

    private static LinkedList<Pair> alterations = 
       (new Lst()).
          pr("IIIII","V").
          pr("IIII","IV").
          pr("VV","X").
          pr("VIV","IX").
          pr("XXXXX","L").
          pr("XXXX","XL").
          pr("LL","C").
          pr("LXL","XC").
          pr("CCCCC","D").
          pr("CCCC","CD").
          pr("DD","M").
          pr("DCD","CM") ;

    public RomanNum() { super();  }
    
    public static String toRoman( Number n) { 
       String s = n.toString();
       Iterator<Pair> guide = alterations.iterator();
       while( guide.hasNext() ) {
           Pair pr = guide.next();
           s = s.replace( pr.fst, pr.snd );
       }
       return s;
    }
    
    public static Number fromRoman(String s) {
       // convert to "III..."
          Iterator<Pair> guide = alterations.descendingIterator();
          while( guide.hasNext() ) {
             Pair pr = guide.next();
             s = s.replace( pr.snd, pr.fst );
          }
       // convert to stone list
          StringCharacterIterator ichar = 
             new StringCharacterIterator(s);
          Number n = new Number();
          for( char c= ichar.first(); 
               c!=StringCharacterIterator.DONE;
               c = ichar.next() 
          ) {
             n.addOne(); 
          }
       return n;
    }

   /// test methods ///

   protected static void p(String s) { System.out.println(s); }

   public static void main( String [] ignore) {
       Number x = fromRoman( "MCMXLIII" ); 
       Number y = fromRoman( "LXXI" );
       if( toDecimal(x)!=1943 ) {
          p("decimal conversion to 1943 failed"); return;
       } else if( !"MCMXLIII".equals(toRoman(x)) ) {
          p("roman conversion to MCMXLIII failed"); return;
       } else if( 71!=toDecimal(y) || !"LXXI".equals(toRoman(y)) )  {
          p("LXXI, 71 conversions failed"); return;
       } else {
          x.add(y);
          if( toDecimal(x)!=2014 || !toRoman(x).equals("MMXIV") ) {
             p("addition failed"); return;
          } else if ( !toRoman(x.sub(y)).equals("MCMXLIII") ) {
             p("subtraction failed"); return;
          }
       }
       p("test passsed!");
   }

}