Table: Courses
+-------------+---------+ +| Column Name | Type | ++-------------+---------+ +| student | varchar | +| class | varchar | ++-------------+---------+ +(student, class) is the primary key (combination of columns with unique values) for this table. +Each row of this table indicates the name of a student and the class in which they are enrolled. ++ +
+ +
Write a solution to find all the classes that have at least five students.
+ +Return the result table in any order.
+ +The result format is in the following example.
+ ++
Example 1:
+ +Input: +Courses table: ++---------+----------+ +| student | class | ++---------+----------+ +| A | Math | +| B | English | +| C | Math | +| D | Biology | +| E | Math | +| F | Computer | +| G | Math | +| H | Math | +| I | Math | ++---------+----------+ +Output: ++---------+ +| class | ++---------+ +| Math | ++---------+ +Explanation: +- Math has 6 students, so we include it. +- English has 1 student, so we do not include it. +- Biology has 1 student, so we do not include it. +- Computer has 1 student, so we do not include it. ++