Note 5 - Prepayments and Deposit to Suppliers (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Cryptocurrency Mining Machine Purchase [Member]
Purchase Agreement Prepayment	$ 1.5
Purchase Agreement, Refund	1.0
Purchase Agreement, Charge-off	0.5
Potential Merger and Acquisition [Member]
Business Combination, Nonrefundable Deposit	$ 1.0