resetting sequence to cur max value

I am migrating a system from hsqldb to postgresql. I have a bunch of
installs of this system live so moving the data is a headache. I was
using identities in hsqldb and now I am using sequences. I was able to
move all my data over however I am having an issue with the sequences. I
default them all to start at a certain number; this works great for a
fresh install.

However when working with existing data the default is < the current
number. ANd I have several installs and they are all different numbers.

Is there a way to set it up so it knows to skip past existing ids?

I would rather an automated solution but I was even trying something like
this:

ALTER SEQUENCE seq_address restart with (select max(id) from address)

I guess that doesn't work because it wants a constant.

Any suggestions?
thanks