Перевести число, записанное римскими...

Uses Crt;
Const
R: Array[1..13] of String[2] =
('I','IV','V','IX','X','XL','L','XC','C','CD','D','CM','M');
A: Array[1..13] of Integer=
(1,4,5,9,10,40,50,90,100,400,500,900,1000);
 
Function Roman(N : Integer) : String;
Var Result : String;
    i      : Integer;
begin
 Result := '';
 i := 13;
 While N >0 do
 begin
   While A[i] >N do Dec(i);
   Result := Result + R[i];
   Dec(N, A[i]);
 end;
 Roman := Result;
end;
 
Function Arabic(S : String) : Integer;
Var Result : Integer;
    i, p   : Integer;
begin
  Arabic := -1;
  Result := 0;
  i := 13;
  p := 1;
  While (p <=Length(S))and(i<>0) do
  begin
    While (i>0)and(Copy(S, p, Length(R[i])) <>R[i]) do
      Dec(i);
    if i<>0 then begin Result := Result + A[i];
    p := p + Length(R[i]) end;
  end;
  if (p=1)and(i=0) then arabic:=-1 else
  If Roman(Result) = S then Arabic := Result
end;
 
Var N, Err : Integer;
    S : String;
BEGIN
clrscr;
   ReadLn(S);
   If S = '' then writeln('byako')
   else begin
   Val(S, N, Err);
   If Err = 0 then
     WriteLn(Roman(N))
   else
     WriteLn(Arabic(S));
     end;
     readln
END.

function IntToRoman(
 
  Value: LongInt
 
):String;