Errata:
!!!!--> In the pattern the CO is 105, which is an ODD number.

• This makes the K2, P2 patt impossible, as you will have 1 stitch left over:
• 105/4 stitches (2 knit, 2 purl)=26.25 <---NOT A WHOLE NUMBER (astutely pointed out by bellux)
• Therefore, I recommend Casting on 104 sts, OR:
• Be aware that at the brim of this hat, you will have a 1 st rib.