From the website:
“Sport or fingering weight yarn: About 350 yd, size 6 or 7 needles, 38 stitches
DK or worsted weight yarn: About 175-200 yd, size 10 or 10.5 needles, 24 stitches
Bulky weight yarn: About 175 yd, size 11 or 13 needles, 20 stitches”

You need an even number of stitches.