var successStream = this.OnCreateRoomAsObservable();
var failureStream = this.OnCreateRoomFailedAsObservable();
successStream.Merge(failureStream)
    .Subscribe(
        unit => { Debug.Log("success!"); },
        exception => { Debug.Log("failed..."); }
    );

// room name you want to join
var roomName = "roomName";

// OnNext --- （ConnectedToMaster => OnJoinedRoom）
var successStream =
    this.OnConnectedToMasterAsObservable().Take(1).IgnoreElements()
        .DoOnCompleted(() =>
            {
                Debug.Log("connect finish!");
                Debug.Log("join room!");
                var roomOptions = new RoomOptions();
                PhotonNetwork.JoinOrCreateRoom(roomName, roomOptions, TypedLobby.Default);
            }
        ).Concat(this.OnJoinedRoomAsObservable());


// OnError --- （OnDisconnected or OnJoinRoomFailed）
var failureStream = this.OnDisconnectedAsObservable()
    .Where(cause => cause != DisconnectCause.None && cause != DisconnectCause.DisconnectByClientLogic)
    .Select(cause =>
    {
        throw PUN2Exception.Create((short) cause, cause.ToString());
        return Unit.Default;
    }).Merge(this.OnCreateRoomFailedAsObservable(), this.OnJoinRoomFailedAsObservable());

Observable.Amb(successStream, failureStream)
    .Subscribe(
        unit => { Debug.Log("join room finish!"); },
        exception => { Debug.Log(exception); })
    .AddTo(this);

Debug.Log("connect!");
PhotonNetwork.ConnectUsingSettings();