Where to check balls go in dishwasher

Trying to put dishwasher back together and am ready to reinstall drain cover and check balls and cannot remember exactly where to put them.

There are two grooves on each side of the impeller. Not sure if one goes in each or if they both just drop into the drain cover.

this image shows the exact situation I am facing.

Thanks
Dishwasher repair question.jpg (80.2 KB)

I found the answer. For anyone who may want to know, you put them in to the drain cover after installing the drain cover in step three in picture of original post.