program cif;

var vstup, i, svstup : longint;

function s(cislo : longint) : longint;
var cifra, suma : longint;
begin

	cifra := 0;
	suma := 0;
	
	while cislo > 0 do
	begin
	
		cifra := cislo mod 10;
		suma := suma + cifra;
		cislo := cislo div 10;
		
	end;

	s := suma;

end;

begin

	repeat
	
		readln(vstup);
		if (vstup = 0) then
			break;
		
		svstup := s(vstup);
		
		i := 11;
		
		while (true) do
		begin
			
			if (svstup = s(vstup*i)) then
			begin
				writeln(i);
				break;
			end;
				
			inc(i);
			
		end;
	
	until vstup = 0;

end.