Really random AIBU, but would be great to have your help please :)
I speak Spanish, so was helping my niece with her Spanish homework last night.
She had to do an adjective agreement exercise where she had to fill in the gaps with the missing word in a few sentences. The missing word was provided in a box, but with the letters jumbled up.
We managed to answer all of the sentences apart from one:
Javier tienne muchos amigos. Es el chico más __ de mi grupo.
(Translation: Javier has lots of friends. He's the most boy in/of my group [of friends]).
The missing word was written out in jumbled letters as: 'cibaosle'. I have a feeling the missing word ends in 'o' to agree with the fact that Javier is a boy, but I'm completely stuck on the rest of the sentence 
Could anyone help please?
Thanks :)