Day 1 splits into two logical steps. Processing the input (which has been imported as a custom asset), summing the parsed values into a new array, and then from that getting the answers to part 1 and part 2.
First collate the input into elves totals:

Then for part 1, the Max Of Int Array
node does the job. For part 2, a new BP function to get the sum of the top N elements, which looks like this:
