<s>[INST] At the end of a 4-month internship, a company wants to select a set of employees for permanent positions. The company has a scoring system in place, which assigns a score to each employee based on their performance. From the list of candidates, the company wants to hire the top-scoring employees, but there are some constraints:

1. The company can hire at most 4 employees from each department.
2. The company cannot hire more than 20 employees in total.

The company has 5 departments, each with 10 employees. The scores are randomly generated for each employee and are to be used in a greedy approach to select the employees for permanent positions. 

Implement a greedy algorithm to select the top-scoring employees while respecting the constraints.[/INST]