Deceasing 1 st each row at neck edge

[Mski]

Hi -
I am working on a vest front and I have 19 stitches on each side with the center stitches on a holder. The pattern calls for decreasing 1 stitch at each neck edge each row for 5 rows so I assume I have to decrease on the purl side, correct? If I use K2tog on one side and ssk on the other side, what decrease do I use on the purl rows?
Thank you in advance -
Mski

[suzeeq]

The p2tog is the back of k2tog.