Dredge

"Dredge" (http://wod.crossfitamped.com/workout/Dredge/80355)
15 min amrap
even minutes - 15 wall ball  (20/14)
odd minutes - 15 box jump  (24/20)
Result: 8 rounds + 2 round of box jumps with 19 reps.

I thought that I must do 20 reps instead of 15. will be retry it again later.