Find The Secret Flag

I am also stuck at this challenge.

@3XPL017 said:
Not sure what you guys are talking about after doing a step it just exits with status 1 instead of 0

I got past that point, I got to “Are you sure it’s the right one? …” after changing some jumps, however that leads to nowhere as I am given some random chars of output.

I also noticed that there is an atoi syscall if a number is passed as an argument, but if you don’t provide it you get directly to the file check. I think the number has to do with the decryption of the flag. However I am unable to see what number needs to be given.

I am trying with ltrace to see the syscalls and exit values and radare2. Any suggestion on how to continue or any other tool that may help?