A Check Condition Question

I apologize if this is something that has been asked before. But I did a search and it kept coming back empty.

I am trying to set up a Check Condition that contains multiple possible answers.

For Instance.

IF State/Province Equals MD;DE:VA then

(It updates another Account field with something specific).

I've tried the above.

I've also tried

IF State/Province IN MD,DE,VA then

I'm kind of new to CRM, so I've been searching all over the place for examples. What I have above should work based on what I've found. But it doesn't And I can't for the life of me figure out why.

If I do it with just ONE of the three it works. So it has to be syntax. But I can't figure out what it should be. Any help would be appreciated.

Thanks.