Shape neck directions are fuzzy

sirdar shawl cardigan 8745

Shape Neck: Work 21 rows dec 1 st at neck edge in 7th and foll
8th row.

Does this mean dec 1 …in 7th, and 8th row
or dec 1 in 7th then 8 rows later or row 15, dec 1 ?

Thanks for the help. This site is great. Been knitting for a few years but never made this pattern before.

In the 7th row, then the 8th row after that. So on r7, and 15.

Thank you so much. Glad I asked, I only have to rip out 1/2 a front piece.