Directions to Ibis Hotel in Berlin from Tegel Airport

[Walter Bright via Digitalmars-d]

On 4/24/2016 10:56 AM, Iain Buclaw via Digitalmars-d wrote:
> On 24 April 2016 at 10:44, Walter Bright via Digitalmars-d
> <digitalmars-d at puremagic.com> wrote:
>> The hotel emailed them to me, I presume they know what they're doing :-) so
>> I thought I'd share:
>>
>> Bus 109 to Jakob-Kaiser-Platz
>> Subway U 7 in the direction of Rudow to Grenzallee
>> Cross the street at the traffic light and turn left. The next street on the
>> right is Jahnstraße.
>> On the left side you will find our hotel.
>
> Conveniently, also the directions to Berghain.  :-)
>

What's the best way to buy a ticket? On the bus itself, or is there a kiosk? 
Credit card?