STOCK-BASED COMPENSATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2022	Aug. 31, 2021
Total stock-based compensation	$ 710	$ 588
Cost of Sales
Total stock-based compensation	91	82
Selling, General and Administrative
Total stock-based compensation	465	395
Research and Development
Total stock-based compensation	$ 154	$ 111