Neat and Easy Solution
#Solution\n\n\nSELECT employee_id FROM Employees WHERE employee_id NOT IN (SELECT employee_id FROM Salaries)\nUNION \nSELECT employee_id FROM Salaries WHERE emp
**#Solution**\n\n\nSELECT employee_id FROM Employees WHERE employee_id NOT IN (SELECT employee_id FROM Salaries)\nUNION \nSELECT employee_id FROM Salaries WHERE employee_id NOT IN (SELECT employee_id FROM Employees)\n\nORDER BY 1 ASC;
['Union Find', 'MySQL']