Advent of Code (AOC) is a series of fun programming challenges released annually from December 1 to 25.

You can find the challenges here: https://adventofcode.com/.

Each day, two challenges are released. Solving each challenge earns you a star, and the ultimate goal is to obtain 50 of them. The second challenge each day is usually a variation of the first one, but requiring more computations, input, or some other thing. Challenges vary in difficulty and are generally easier than competitive programming challenges. Each challenge is written in English, with your input provided in a text file and the expected output being a single line (usually a number).

These challenges are language-agnostic, meaning you don't need to solve them in a specific programming language. Some of the more esoteric solutions found online use spreadsheets and Vim commands. You could even use paper and pencil!