Function toBin(dec: integer): string;
var
  buf: integer;
  str: string;
begin
  buf := dec;
  repeat
    str := concat(IntToStr(buf mod 2), str);
    buf := buf div 2;
  until (buf = 0);
  toBin := str;
end;

procedure toBin(dec: integer; var bin: string);
var
  buf: integer;
begin
  buf := dec;
  repeat
    bin := concat(IntToStr(buf mod 2), bin);
    buf := buf div 2;
  until (buf = 0);
end;

var
  s: string;

begin
  writeln(toBin(10));
  toBin(10, s);
  writeln(s);
end.