in Egypt you say
if you are talking to a man
"kol sana wenta tayeb"
to a woman
"kol sana wenty tayeba"
to a lot of people
"kol sana wentom tayebeen"
and you reply
to a man: "wenta tayeb"
to a woman: "wenty tayeba"
to a bunch of people: "wentom tayebeen"
:D
so kol sana wenty tayeba :)