program check;

var
   input : string;
   a : array[1..12] of char;
   i : word;
   c : char;
   successful : boolean;

function is_valid_char(c : char) : boolean;

var
	i : word;
	successful2 : boolean;
begin
	successful2 := false;

	for i := 1 to 12 do
	begin
		if c = a[i] then //Does the character match the valid character at index i?
		begin
			successful2 := true; //Yes it does, set successful to true

			break; //Stop loop, character is valid
		end;
	end;

	exit(successful2); //If the character didn't match any of the values in the array then successful will still be false
end;

begin
	write('Enter a string: ');
	readln(input);

	a[1] := 'i';
	a[2] := 'I';
	a[3] := 'V';
	a[4] := 'v';
	a[5] := 'C';
	a[6] := 'c';
	a[7] := 'D';
	a[8] := 'd';
	a[9] := 'L';
	a[10] := 'l';
	a[11] := 'M';
	a[12] := 'n';

	successful := true; //Set this to true so that if there are no invalid characters you can tell it succeeded

	for i := 1 to length(input) do
	begin
		c := input[i]; //Get the array value of 'input' at index 'i'

		if is_valid_char(c) <> true then //Is the character valid?
		begin
			successful := false; //We found an invalid character, set successful to false

			break; //Break out of the loop, no point checking the rest
		end;
	end;


	if successful = true then //If there was an invalid character then successful would have been set to false

	Begin
	rn:='';
	ReadLn(input);
	Temp:=input;

	Repeat
		If (Temp = M)Then Begin
			D:=Temp Div 1000;
			For i:=1 To D Do Begin
				rn:=rn+'M';
		End;

		Temp:= Temp Mod 1000;
    End

    Else Temp:= Temp Mod 1000;

    If (Temp Div 100 <> 0)Then Begin
		D:=Temp Div 100;
		Case (D) Of
			1:rn:=rn+'C';
			2:rn:=rn+'CC';
			3:rn:=rn+'CCC';
			4:rn:=rn+'CD';
			5:rn:=rn+'D';
			6:rn:=rn+'DC';
			7:rn:=rn+'DCC';
			8:rn:=rn+'DCCC';
			9:rn:=rn+'CM';
		End;
        Temp:=Temp Mod 100;
	End;

    If (Temp Div 10 <> 0) Then Begin
		D:=Temp Div 10;
		Case (D) Of
			1:rn:=rn+'X';
			2:rn:=rn+'XX';
			3:rn:=rn+'XXX';
			4:rn:=rn+'XL';
			5:rn:=rn+'L';
			6:rn:=rn+'LX';
			7:rn:=rn+'LXX';
			8:rn:=rn+'LXXX';
			9:rn:=rn+'XC';
        End;
        Temp:=Temp Mod 10;
    End;

    Case (Temp) Of
        1:rn:=rn+'I';
        2:rn:=rn+'II';
        3:rn:=rn+'III';
        4:rn:=rn+'IV';
        5:rn:=rn+'V';
        6:rn:=rn+'VI';
        7:rn:=rn+'VII';
        8:rn:=rn+'VIII';
        9:rn:=rn+'IX';
    End;

	Until Temp <= 10;
	Write(User,'=',rn);
	readln();

end.