chick@about $ whoami
Student from Xidian University majoring in Cyberspace Security, class of 2022.
Pwner in XDSEC & L-Team.

I can type cat /flag to get the flag. (After get (root) shell)
$ cat /flag
flag{ch1c4_f@ke_f1ag}$ cat /flag
cat: /flag: Permission denied
$ ?
sh: 2: ?: not found