Hello! I need some help. I have a large list of items separated by the name of the item. Each row has a length for the item as well as its name.

I've grouped the items according to the names, but I want to sum the item lengths according to each name.

For example, for the "10K1" group, I want to summarize all lengths so I can create a cell that says: 10K1, Length X
Then I want to do the same with my "W18X35" group, "24K4" group, and so on. I have ~30 of these groups of items and I need a total length for each one.

How would I go about this? Here's a photo where A is item lengths and B is item names:
Annotation 2020-08-05 110558.png