# [Day 3](https://adventofcode.com/2022/day/3) :gift::gift::gift: Today's language: **C** All the characters (the Elf's items) occuring in (half) a line (backpack) are stored as bits in an unsigned long, duplicate characters can then be determined by bitwise and-ing these numbers. ```shell # Find the item type that appears in both compartments of each rucksack. What is the sum of the priorities of those item types? gcc main.c -o day3 ./day3 ```