How to calculate end of the salary

We would like to inform you that the Qatari Labor Law grants the worker the right to get the end of services benefits which is 3 week wage per year of services, and calculated according to the last wage.
Below the related article:
Article (54):
In addition to any sums to which the worker is entitled to upon the expiry of his service, the employer shall pay the end of service gratuity to the worker who has completed employment of one year or more. This gratuity shall be agreed upon by the two parties, provided that it is not less than a three-week wage for every year of employment. The worker shall be entitled to gratuity for the fractions of the year in proportion to the duration of employment.
The worker’s service shall be considered continuous if it is terminated in cases other than those stipulated in article (61) of this Law and is returned to service within two months of its termination.
The last basic wage shall be the base for the calculation of the gratuity.
The employer is entitled to deduct from the service gratuity the amount due to him by the worker.