Table: `ActorDirector`

    +-------------+---------+
    | Column Name | Type    |
    +-------------+---------+
    | actor_id    | int     |
    | director_id | int     |
    | timestamp   | int     |
    +-------------+---------+
    timestamp is the primary key column for this table.

Write a SQL query for a report that provides the pairs `(actor_id, director_id)` where the actor has cooperated with the director at least three times.

Return the result table in any order.

The query result format is in the following example.

Example 1:

    Input:
    ActorDirector table:
    +-------------+-------------+-------------+
    | actor_id    | director_id | timestamp   |
    +-------------+-------------+-------------+
    | 1           | 1           | 0           |
    | 1           | 1           | 1           |
    | 1           | 1           | 2           |
    | 1           | 2           | 3           |
    | 1           | 2           | 4           |
    | 2           | 1           | 5           |
    | 2           | 1           | 6           |
    +-------------+-------------+-------------+
    Output:
    +-------------+-------------+
    | actor_id    | director_id |
    +-------------+-------------+
    | 1           | 1           |
    +-------------+-------------+
    Explanation: The only pair is (1, 1) where they cooperated exactly 3 times.