Annual report pursuant to Section 13 and 15(d)

Consolidated Balance Sheets (Parenthetical)

v3.20.2
Consolidated Balance Sheets (Parenthetical) - $ / shares
May 31, 2020
May 31, 2019
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 5,000,000 5,000,000
Common stock, par value $ 0.001 $ 0.001
Common stock, shares authorized 700,000,000 700,000,000
Common stock, shares issued 519,261,580 329,554,763
Common stock, shares outstanding 518,975,572 329,395,752
Treasury stock, shares 286,008 159,011
Treasury Stock    
Common stock, par value $ 0.001 $ 0.001
Series D Convertible Preferred Stock    
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 11,737 11,737
Preferred stock, shares issued 8,452 0
Preferred stock, shares outstanding 8,452 0
Series B Convertible Preferred Stock    
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 400,000 400,000
Preferred stock, shares issued   92,100
Preferred stock, shares outstanding 92,100 92,100
Series C Convertible Preferred Stock    
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 8,203 8,203
Preferred stock, shares issued 8,203 3,246
Preferred stock, shares outstanding 8,203 3,246