While walking in a small alley in Paris, you come across a safe.
The number pad looks like this :
There are things on the back of the safe too :
"À l'aide du carré 3x3 ci-dessous et des nombres périphériques jaunes, déterminez le code du coffre-fort.
Entrez la combinaison trouvée sur le pavé numérique, puis appuyez sur 'Ouvrir'."
What are the buttons you have to press on the number pad in order to open the safe ?
Hint#1:
The number behind the "?" isnt created using the same formula as the other white numbers. Despite this, there still are 4 ways to find it.