Help for shape side for arm holes

I currently been knitting for a year and I am stuck on understanding the pattern

Bernat pattern 530197 - Cable cape

So I have made it through the cable and working on the back body part

Ok with 2nd row: K2. P2 rep to last 2 sts K2 - 3rd row P2 K2 rep to last 2sts P2
4 row P2 K2 rep to last 2sts. P2
5th row K2 P2 rep to last 2 sts K2

All good till shape sides
Pattern reads as ending with WS keeping cont of pat, dec 1st each end of ext 3 (3-3-15(sizes I’m do medium so it’s 3)) rows. 68 sts rem form medium size. Work 1 row even in pat. The. It rep the same till I end up with 50 sts. Then it has keeping cont of pat, dec 1 st each end of next row and following alt rows until 26 sts rem.

So question is that I am decreasing at each end of the NEXT 3 rows or am I to skip rows and decrease every 3rd row…

Pattern reads as ending with WS keeping cont of pat, dec 1st each end of ext 3 (3-3-15(sizes I’m do medium so it’s 3)) rows. 68 sts rem form medium size. [B]Decrease at each end of the next 3 rows
[/B] Work 1 row even in pat. The. It rep the same till I end up with 50 sts.
Then it has keeping cont of pat, dec 1 st each end of next row and following alt rows until 26 sts rem.[B] Decrease at each end of the next row. Then work a row without dec, work a dec row, work a row without dec etc until there are 26sts (so you’re decreasing every other row in this last direction).
[/B]

Great. Thank you.