Find shortest path in an OOP maze

You are working in a codebase that models a maze using object-oriented classes. The maze contains open cells and walls. You are given an entrance cell and an exit cell. Implement a function that returns the length of the shortest path from entrance to exit using 4-directional movement (up/down/left/right). If no path exists, return `-1`. ## Provided Interfaces (conceptual) Assume you are given objects with methods similar to: - `maze.get_entrance() -> Cell` - `maze.get_exit() -> Cell` - `maze.get_neighbors(cell: Cell) -> List[Cell]` Returns adjacent cells you can move to (already excludes walls/out-of-bounds). - `cell.id` (or any stable identity / coordinates) You may assume `Cell` objects can be used to identify visited states (via `id`, coordinates, or hashing). ## Input - A `Maze` object as described. ## Output - Integer shortest distance (number of moves) from entrance to exit, or `-1`. ## Constraints - Maze can be large; your solution should be `O(V+E)` where `V` is number of reachable cells. ## Example If the shortest route requires 7 moves, return `7`.