Please note that there have been some inquiries about this, so here's a clarification just in case it's needed:

Row 5 of the Slip St pattern is correct as written.
The "last 2 sts" include the k1 from the final rep of "sl 1 wyib, k1", thus ending the pattern rep with k2, followed by k3 for Garter Edge.

The 81 sts are worked as follows on Rows 5 and 6:
Row 5 K3 for Garter edge; k2, *sl 1 wyib, k1; rep from * 34 times more, sl 1 wyib, k2; k3 for Garter edge.
Row 6 K3 for Garter edge; p2, *sl 1 wyif, p1; rep from * 34 times more, sl 1 wyif, p2; k3 for Garter edge.