We can’t speak French and just say what we see.
We also don’t know what underscores are add them yourself.
put ONLY the final decrypted cipher in bcactf{}, no intermediate steps
key - vinegar
cipher 0 - mmqaonv
cipher 1 - seooizmt
cipher 2 - bdoloeinbdjmmyg <- THIS ONE
The challenge description hints towards Vigenere’s cipher. We can just use an online decryption tool.
Each cipher, decrypted, becomes the key for the next cipher.
bcactf{add_to_salad_yummy}