"""
WEB skeleton — copy & fill. (p4-team style: read the source, find the
sanitization-order bug, then script the request.)

Key lesson from 'piapiapia': filter() ran AFTER serialize() -> length
manipulation / object injection. Always diff the order of sanitize vs use.
"""
import requests

BASE = "http://challenge.host:port"
S = requests.Session()


def get_token():
    r = S.get(BASE + "/login")
    # parse CSRF / cookies as needed
    return None


def exploit():
    # 1) Find the input that bypasses validation (array, encoding, filter order).
    # 2) Craft payload.
    # 3) Send & parse response for flag.
    r = S.post(BASE + "/endpoint", data={"nickname[]": "PAYLOAD"})
    print(r.text)


if __name__ == "__main__":
    exploit()