1. Read the hex value contents of `out.txt`.
2. Generate the pseudo-random key by using the same seed `13371337`.
3. XOR the contents of `out.txt` with the generated key.
4. Write the XORed value onto `flag.txt`.
5. Represent the hex value of the key in ASCII using `xxd`.

Original writeup (https://kblagoev.com/blog/soulcrabber-cyberapocalypse-2021-ctf/).