Note 7 - Leases - Summary of Lease Activity (Details) - USD ($)	3 Months Ended
	Aug. 31, 2023	Aug. 31, 2022
Amortization of right-of-use assets	$ 7,699	$ 218,914
Interest on lease liabilities	600	19,509
Operating lease expense	183,957	52,970
Short-term lease expense	360,353	395,810
Total	552,609	687,203
Operating cash flows	600	19,509
Financing cash flows	9,947	419,120
Operating cash flows	$ 177,217	$ 52,970
Financing leases (Year)	1 year 7 months 6 days	1 year 1 month 6 days
Operating leases (Year)	13 years 10 months 24 days	14 years 9 months 18 days
Financing leases	4.30%	7.30%
Operating leases	6.00%	6.00%