Le Sot
To get into the public bucket we can use this url
https://cloud-intro-challenge.s3.gra.io.cloud.ovh.net/
We can see that there is an endpoint les-moutons.json appearing in the body of the page. Try to access this endpoint and we get the flag
Flag: 404CTF{D35_m0utOns_D4n5_13s_NU@g3s}