You have a movie renting company consisting of `n` shops. You want to implement a renting system that supports searching for, booking, and returning movies. The system should also support generating a report of the currently rented movies.

Each movie is given as a 2D integer array `entries` where `entries[i] = [shopi, moviei, pricei]` indicates that there is a copy of movie `moviei` at shop `shopi` with a rental price of `pricei`. Each shop carries at most one copy of a movie `moviei`.

The system should support the following functions:

- Search: Finds the cheapest 5 shops that have an unrented copy of a given movie. The shops should be sorted by price in ascending order, and in case of a tie, the one with the smaller `shopi` should appear first. If there are less than 5 matching shops, then all of them should be returned. If no shop has an unrented copy, then an empty list should be returned.
- Rent: Rents an unrented copy of a given movie from a given shop.
- Drop: Drops off a previously rented copy of a given movie at a given shop.
- Report: Returns the cheapest 5 rented movies (possibly of the same movie ID) as a 2D list `res` where `res[j] = [shopj, moviej]` describes that the `jth` cheapest rented movie `moviej` was rented from the shop `shopj`. The movies in `res` should be sorted by price in ascending order, and in case of a tie, the one with the smaller `shopj` should appear first, and if there is still tie, the one with the smaller `moviej` should appear first. If there are fewer than 5 rented movies, then all of them should be returned. If no movies are currently being rented, then an empty list should be returned.

Implement the `MovieRentingSystem` class:

- `MovieRentingSystem(int n, int[][] entries)` Initializes the `MovieRentingSystem` object with `n` shops and the movies in `entries`.
- `List<Integer> search(int movie)` Returns a list of shops that have an unrented copy of the given `movie` as described above.
- `void rent(int shop, int movie)` Rents the given `movie` from the given `shop`.
- `void drop(int shop, int movie)` Drops off a previously rented `movie` at the given `shop`.
- `List<List<Integer>> report()` Returns a list of cheapest rented movies as described above.

Note: The test cases will be generated such that `rent` will only be called if the shop has an unrented copy of the movie, and `drop` will only be called if the shop had previously rented out the movie.

Example 1:

    Input

    ["MovieRentingSystem", "search", "rent", "rent", "report", "drop", "search"]

    [[3, [[0, 1, 5], [0, 2, 6], [0, 3, 7], [1, 1, 4], [1, 2, 7], [2, 1, 5]]], [1], [0, 1], [1, 2], [], [1, 2], [2]]

    Output

    [null, [1, 0, 2], null, null, [[0, 1], [1, 2]], null, [0, 1]]

    Explanation

    MovieRentingSystem movieRentingSystem = new MovieRentingSystem(3, [[0, 1, 5], [0, 2, 6], [0, 3, 7], [1, 1, 4], [1, 2, 7], [2, 1, 5]]);

    movieRentingSystem.search(1);  // return [1, 0, 2], Movies of ID 1 are unrented at shops 1, 0, and 2. Shop 1 is cheapest; shop 0 and 2 are the same price, so order by shop number.

    movieRentingSystem.rent(0, 1); // Rent movie 1 from shop 0. Unrented movies at shop 0 are now [2,3].

    movieRentingSystem.rent(1, 2); // Rent movie 2 from shop 1. Unrented movies at shop 1 are now [1].

    movieRentingSystem.report();   // return [[0, 1], [1, 2]]. Movie 1 from shop 0 is cheapest, followed by movie 2 from shop 1.

    movieRentingSystem.drop(1, 2); // Drop off movie 2 at shop 1. Unrented movies at shop 1 are now [1,2].

    movieRentingSystem.search(2);  // return [0, 1]. Movies of ID 2 are unrented at shops 0 and 1. Shop 0 is cheapest, followed by shop 1.

Constraints:

- `1 <= n <= 3 * 105`
- `1 <= entries.length <= 105`
- `0 <= shopi < n`
- `1 <= moviei, pricei <= 104`
- Each shop carries at most one copy of a movie `moviei`.
- At most `105` calls in total will be made to `search`, `rent`, `drop` and `report`.