about operator "--"

Question

I seem really don't understand why this program is not able to output.
Hope that I can get your help,thanks a lot.
---from a Chinese starter
https://code.sololearn.com/cUWOg8BQb1r0/?ref=app

Answer 1

use "<<" instead of ">>" in cout statement and also <<"\n" is proper instead of \n

Answer 2

it runs well now,thanks all of you ☺️