[https://rawsec.ml/en/NeverLAN-CTF-2018-writeups/#50-more-basic-math-scripting](https://rawsec.ml/en/NeverLAN-CTF-2018-writeups/#50-more-basic-math-scripting)

Original writeup (https://rawsec.ml/en/NeverLAN-CTF-2018-writeups/#50-more-basic-math-scripting).