Step 1: Map out the seating based on the clues given. Peter is at 102, Maria at 104, Tom at 101, and Max at 106.
Step 2: Identify the middle seat between Maria (104) and Max (106), which is 105, but there's an inconsistency with the question's clue of John in the middle of Max and Maria. Assume middle means direct middle seat numerically between Maria and Max.
Step 3: Correctly identifying that John was sitting in seat 104, based on the information given and logical seating arrangement.