Row 1 (RS): P1, k2tog, yo, (k1, yo, k1) in next st, yo, ssk, *p3, k2tog, yo, (k1, yo, k1) in next st, yo, ssk, repeat from * to last st, p1 (multiple of 10 sts, plus 9).
Row 2: K1, p1, k1, sl1 wyif, p1, sl1 wyif, k1, p1, *k3, p1, k1, sl1 wyif, p1, sl1 wyif, k1, p1, repeat from * to last st, k1.