Intent to Return from Sick Leave. Employees on sick leave shall advise the Employer not later than one (1) day before the expiration of such leave of their intent to return to employment, unless they have obtained a written consent of the Employer for a leave of absence beyond expiration of said leave. Failure to return to employment or failure to negotiate a leave of absence in accordance with this Agreement shall be construed as a resignation to take effect at the end of the sick leave. In such event, the provisions of Article 18 on severance pay shall not apply.