I pulled up my can collection website and had her start reading off the names of the cans he had. In the end, he had ten cans that I didn't.
But I have them now.
I am in no hurry to complete these two sets. I now have 15 of the 70 cans from 1977 and I have 54 of the 100 cans from the 1978 set. It's a slow process, but hopefully someday I'll have complete collections from both years.