MCO can get kind of confusing - A is Airsides 1 and 2 (north side), B is 3 and 4 (south side) - that's all based on the roadways entering the terminal area (really it's one terminal building with two sides, A and B, yet they call each a seperate terminal...). Then the airsides/security are divided into East/West sides which can make it confusing at times...