var x, d, x0, N: longint;

begin
for i : longint := 0 to 10000 do
begin
  x := i;
  x0 := x; N := 0;
  while x > 0 do 
  begin
    d := x mod 4;
    N := 10*N + d;
    x := x div 4
  end;
  N := N + x0;
  if N > 10300 then 
  begin
    writeln(x0);
    break
  end;
end;
end.