import hashlib
import binascii

def mystery(x):
    if not isinstance(x, str):
        return False

    # normalize: trim outer whitespace, force lowercase
    s = x.strip().lower()

    # structural constraints (to discourage brute force by "random strings")
    if len(s) != 9:
        return False
    if not (s.isalnum() and any(c.isalpha() for c in s) and any(c.isdigit() for c in s)):
        return False
    if s[0] == "0" or s[-1] == "0":
        return False
    if sum(ord(c) for c in s) % 7 != 0:
        return False

    # "hard" condition: a composite hash check
    h1 = hashlib.sha256(s.encode("utf-8")).hexdigest()
    h2 = hashlib.md5((s[::-1] + "|" + s).encode("utf-8")).hexdigest()

    # require that XOR of selected bytes hits an exact target sequence
    b1 = binascii.unhexlify(h1)  # 32 bytes
    b2 = binascii.unhexlify(h2)  # 16 bytes

    # 10-byte signature assembled from mixed positions
    sig = bytes([
        b1[0] ^ b2[0],
        b1[5] ^ b2[1],
        b1[10] ^ b2[2],
        b1[15] ^ b2[3],
        b1[20] ^ b2[4],
        b1[25] ^ b2[5],
        b1[30] ^ b2[6],
        b1[31] ^ b2[7],
        b1[1] ^ b2[8],
        b1[2] ^ b2[9],
    ])

    return sig == b"\x13\x37\x13\x37\x13\x37\x13\x37\x13\x37"

import hashlib
import re

def mystery(x):
    # Accept either a number or a string; normalize to a compact ASCII string.
    if isinstance(x, (int, float)):
        s = repr(x)
    elif isinstance(x, str):
        s = x
    else:
        return False

    s = s.strip()

    # Keep it narrow enough to discourage random brute force, but not too obvious.
    # Format: abcd-efgh-ijkl (lowercase base32-ish, no i/l/o/u to reduce ambiguity)
    if len(s) != 14:
        return False
    if s[4] != "-" or s[9] != "-":
        return False

    a = s.replace("-", "")
    if len(a) != 12:
        return False
    if not re.fullmatch(r"[0-9a-hjkmnp-tv-z]{12}", a):
        return False

    # Mild structural checksum to reduce search space further
    if sum((i + 1) * ord(c) for i, c in enumerate(a)) % 97 != 42:
        return False

    # "Hard" condition: target a truncated SHA-256 digest (24 bits).
    # This is solvable (there are many preimages) but hard to guess without running code.
    h = hashlib.sha256(a.encode("ascii")).digest()
    tag = (h[0] << 16) | (h[1] << 8) | h[2]
    return tag == 0xC0FFEE

import hashlib
import re

def mystery(x):
    # Accept either a number or a string; normalize to a plain string.
    if isinstance(x, (int, float)):
        s = format(x, ".17g")  # stable-ish textual form
    elif isinstance(x, str):
        s = x
    else:
        return False

    s = s.strip().lower()

    # Require a specific "license-like" shape to narrow the domain.
    # Example shape: xxxx-xxxx-xxxx where x is [0-9a-f]
    if not re.fullmatch(r"[0-9a-f]{4}(?:-[0-9a-f]{4}){2}", s):
        return False

    payload = s.replace("-", "")  # 12 hex chars => 6 bytes

    # Non-obvious checksum constraint (discourages casual guessing)
    b = bytes.fromhex(payload)
    if (sum((i + 1) * b[i] for i in range(len(b))) ^ 0x5A) % 97 != 13:
        return False

    # Hard condition: match a truncated hash signature.
    # (48-bit target; extremely hard to solve by inspection.)
    h = hashlib.sha256(payload.encode("ascii")).digest()
    tag48 = int.from_bytes(h[:6], "big")
    return tag48 == 0x314159265358

import hashlib
import re

def mystery(x):
    # accept either a number or a string; normalize to a strict ASCII string
    if isinstance(x, (int, float)):
        s = format(x, ".17g")
    elif isinstance(x, str):
        s = x
    else:
        return False

    s = s.strip().lower()

    # Narrow domain: 16 lowercase hex chars, grouped like a key
    # Example: dead-beef-cafe-babe  (total 19 chars including dashes)
    if not re.fullmatch(r"[0-9a-f]{4}(?:-[0-9a-f]{4}){3}", s):
        return False

    payload = s.replace("-", "")  # 16 hex chars
    b = bytes.fromhex(payload)    # 8 bytes

    # Mild extra structure constraints (discourage blind guessing)
    if (b[0] ^ b[7]) != 0xAA:
        return False
    if (sum(b) + (b[1] << 1) + (b[3] << 2)) % 251 != 42:
        return False

    # Hard condition: truncated SHA-256 signature over the undashed payload
    h = hashlib.sha256(payload.encode("ascii")).digest()
    tag32 = int.from_bytes(h[:4], "big")
    return tag32 == 0xC0DEC0DE

import re
import zlib
import hashlib

def mystery(x):
    # Accept string or number; normalize to a compact string
    if isinstance(x, (int, float)):
        s = format(x, ".17g")
    elif isinstance(x, str):
        s = x
    else:
        return False
    s = s.strip()

    # Narrow "key-like" format: 4 groups of 4 uppercase hex chars
    # Example: 1A2B-3C4D-5E6F-7788
    if not re.fullmatch(r"[0-9A-F]{4}(?:-[0-9A-F]{4}){3}", s):
        return False

    payload = s.replace("-", "")          # 16 hex chars
    b = bytes.fromhex(payload)            # 8 bytes

    # A couple of opaque, non-cryptographic constraints
    if (b[0] + b[2] + b[4] + b[6]) % 17 != 3:
        return False
    if ((b[1] ^ b[3] ^ b[5] ^ b[7]) & 0xFF) != 0x5A:
        return False

    # "Hard" condition: composite signature from two different hashes
    h = hashlib.sha256(payload.encode("ascii")).digest()
    c = zlib.crc32(payload.encode("ascii")) & 0xFFFFFFFF

    tag = (int.from_bytes(h[:4], "big") ^ c) & 0xFFFFFFFF
    return tag == 0xC0FFEE42