Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Nov. 30, 2024	Nov. 30, 2023
Operating activities
Net income	$ 3,722,815	$ 3,829,211
Adjustments to reconcile net income to net cash flows from operating activities
Depreciation	833,399	910,956
Amortization	11,112	0
Stock options issued for services	731,204	301,308
Changes in other assets and liabilities
Accounts and other receivables, net	(3,035,297)	1,481,404
Inventory	(946,432)	(1,224,268)
Costs and estimated earnings in excess of billings	1,338,924	2,401,673
Other current assets	(1,374,126)	271,607
Accounts payable	(581,496)	(549,722)
Accrued expenses	(2,293,115)	(1,045,751)
Billings in excess of costs and estimated earnings	(1,893,366)	1,013,546
Other assets	0	(27,343)
Net operating activities	(3,486,378)	7,362,621
Investing activities
Acquisition of property and equipment	(970,569)	(544,801)
Purchase of short-term investments	(2,615,003)	(7,234,549)
Proceeds from sale of short-term investments	6,500,000	0
Other investing activities	(2,460)	(2,493)
Net investing activities	2,911,968	(7,781,843)
Financing activities
Proceeds from issuance of common stock, net	229,814	20,875
Acquisition of treasury stock	(131,542)	(15,799)
Net financing activities	98,272	5,076
Net change in cash and cash equivalents	(476,138)	(414,146)
Cash and cash equivalents - beginning	2,831,471	3,575,219
Cash and cash equivalents - ending	$ 2,355,333	$ 3,161,073