var
  s, p2: string;
  a, b, p1, a1, b1, i: integer;
  bol: boolean;

function swap(s: string): string;
var
  i, j: integer;
  x: char;
begin
  i := 1;
  j := length(s);
  while (i < j) do
  begin
    x := s[i];
    s[i] := s[j];
    s[j] := x;
    inc(i);
    dec(j);
  end;
  swap := s;
end;

procedure wiwod(n: integer);
begin
    if (n < 10) then
      writeln('0', n, ':', swap(inttostr(n)), '0')
    else
      writeln(n, ':', swap(inttostr(n)))
end;

begin
  readln(s);
  delete(s, 3, 1);
  b := strtoint((copy(s, 3, 2)));
  a := strtoint((copy(s, 1, 2)));
  a1 := a;
  b1 := b;
  bol := true;

  for i := a1 * 60 + b1 + 1 to 1440 do
  begin
    a := i div 60;
    b := i mod 60;
    if ((a >= a1) or (b >= b1)) and (a = strtoint(swap(inttostr(b)))) then
    begin
      bol := false;
      wiwod(a);
      break;
    end;
  end;

  if (bol) then
    writeln('00:00');

  readln;
  readln;
end.