Schedule of Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Income Per Share of Common Stock -
Net income attributable to common stockholders	$ 452,458	$ 633,456	$ 3,044,535	$ 2,366,837
Weighted-average shares outstanding - basic	28,472,639	28,361,201	28,472,256	28,361,201
Income per share of common stock – basic	$ 0.02	$ 0.02	$ 0.11	$ 0.08
Net income attributable to common stockholders	$ 452,458	$ 633,456	$ 3,044,535	$ 2,366,837
Add: Preferred stock dividends for assumed conversion			243,082	243,973
Net income allocated to common stockholders			$ 3,287,617	$ 2,610,810
Incremental shares from assumed conversion of warrants or options, as appropriate	494,505	667,956	3,828,828	4,001,811
Weighted average common stock outstanding - diluted	28,967,144	29,029,157	32,301,084	32,363,012
Income (loss) per share of common stock – diluted	$ 0.02	$ 0.02	$ 0.10	$ 0.08