Unmatched Rows on Either Side

List students who have no fee record and fee records that belong to no student. Return item and issue, ordered by item. (Emulate a FULL OUTER JOIN anti-match with UNION ALL.)

Table schema

Students(id INT PRIMARY KEY, name VARCHAR(20))
Fees(student_id INT, amount INT)

Sample data

Students
id | name
1 | Ann
2 | Bob
3 | Cy

Fees
student_id | amount
1 | 500
3 | 300
4 | 200