What should I do after accidentally extinguishing a cigarette in Zamzam water?

Previous fatwas have ruled on the impermissibility of smoking and the virtue of Zamzam water. Extinguishing cigarettes with Zamzam water is not sinful, but it does not remove impurity, nor should it be used to wash the dead. Rather, it is disliked, and some scholars have gone so far as to deem it forbidden to remove impurity with it. Therefore, Zamzam water must be protected from such matters. If you did so unintentionally without intending disrespect, there is no blame, but repentance from smoking and quitting it is obligatory.