Shift the ribbing pattern (Knit 2 Purl 2) 1 stitch to the left every four rounds. Repeat this until your sock is 28 cm (11 inches), 32 cm ( ... inches) or 36 cm ( ... inches) long for socks in the size 35-37 ( ... US), 38-40 ( ... US) or 41-43 ( ... to
