What is the cost of keeping an alliance active?

I have three corps with 322 members in total.
If I make an alliance, how many ISKs will the three corps have to pay to keep the alliance active?

I know the cost is monthly, but I don’t understand how much for each alliance.

does it depend on the number of members???
there is any updated official post from ccp ???

any one ???

4mill a month or something for Alliance Maintenance fees

Basically, the big bill is the creation - keeping it ticking over is peanuts

It’s a billion to create, then 2 mil per month per corp. If you have 3 corps it’s 6 mil a month.