How do I get my Microsoft Exchange contacts to iCloud?

For some reason all my iCloud contacts got deleted, but thank God I have Microsoft Exchange which has all my contacts.

I'd like to get rid of my MS Exchange though, because why pay for email when I have iCloud for free???

So, how do I get the MS Exchange contacts over to iCloud?

I am on a MacBook Air running OSX Mountain Lion, all updates installed.

Thank you for you help in advance!!