Note 6 - Stockholders' Equity - Warrants (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Outstanding (in shares)	314,572
Outstanding (in dollars per share)	$ 0.5
Outstanding (Year)		1 month 6 days
Outstanding	$ 0	$ 59,737
Issued, number of shares (in shares)	0
Issued, weighted average exercise price (in dollars per share)	$ 0
Exercised, number of shares (in shares)	(103,500)
Exercised, weighted average exercise price (in dollars per share)	$ 0.5
Expired or cancelled, number of shares (in shares)	(211,072)
Expired or cancelled, weighted average exercise price (in dollars per share)	$ 0.5
Outstanding (in shares)	0	314,572
Outstanding (in dollars per share)	$ 0	$ 0.5