script.py

import binascii
import gmpy2

gmpy2.get_context().precision = 2048
# `x = p + q`
x = gmpy2.mpz(0x17fef88f46a58da13be8083b814caf6cd8d494dd6c21ad7bf399e521e14466d51a74f51ad5499731018b6a437576e72bd397c4bb07bfbb699c1a35f1f4fa1b86dee2a1702670e9cea45aa7062f9569279d6d4b964f3df2ff8e38cf029faad57e42b831bde21132303e127cba4e80cd3c9ff6a7bad5b399a18252dc35460471ea8)
n = gmpy2.mpz(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)
c = gmpy2.mpz(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)
e = 65537

# https://www.degruyter.com/document/doi/10.1515/jmc-2016-0046/html
p = gmpy2.mpz((x+gmpy2.sqrt(x**2-4*n))/2)
q = gmpy2.mpz(n/p)

print(f'p = {p:x}')
print(f'q = {q:x}')

# The next two lines were also given in `gen.py`
m = gmpy2.lcm(p - 1, q - 1)
d = pow(e, -1, m)

decrypted_text = pow(c, d, n)
# [2:] slicing, to strip the 0x part
print("Flag: %s" % binascii.unhexlify(hex(decrypted_text)[2:]).decode())