Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Aug. 31, 2024	Aug. 31, 2023
Operating activities
Net income	$ 2,666,655	$ 1,847,863
Adjustments to reconcile net income to net cash flows from operating activities
Depreciation	380,178	455,478
Amortization	5,556	0
Changes in other assets and liabilities
Accounts and other receivables, net	(1,567,171)	149,754
Inventory	(345,691)	(918,507)
Costs and estimated earnings in excess of billings	23,467	735,211
Other current assets	(892,391)	229,533
Accounts payable	409,075	(666,200)
Accrued expenses	(1,652,262)	(1,615,575)
Billings in excess of costs and estimated earnings	(2,616,913)	2,820,563
Net operating activities	(3,589,497)	3,038,120
Investing activities
Acquisition of property and equipment	(246,962)	(427,652)
Purchase of short-term investments	(341,416)	(3,297,983)
Proceeds from sale of short-term investments	3,500,000	0
Other investing activities	(1,113)	(1,128)
Net investing activities	2,910,509	(3,726,763)
Financing activities
Proceeds from issuance of common stock, net	11,013	18,682
Acquisition of treasury stock	0	(15,799)
Net financing activities	11,013	2,883
Net change in cash and cash equivalents	(667,975)	(685,760)
Cash and cash equivalents - beginning	2,831,471	3,575,219
Cash and cash equivalents - ending	$ 2,163,496	$ 2,889,459