#! /usr/bin/env python3
import os
import random
import string
from hashlib import sha256

flag = "maple{sebastianflagrotthirteen}"
assert flag.startswith("maple{") and flag.endswith("}")
flag = flag[6:-1]

alphabet = "".join(random.sample(string.ascii_lowercase, k=26))
encoded = "".join(alphabet[(alphabet.index(c) + 13) % 26] for c in flag)

print("checksum:   ", sha256(encoded.encode()).hexdigest())
print("flag(rot13):", encoded)