Você considerou que a lista terá sempre 3 caracteres, mas não foi definida a quantidade específica nas instruções

you almost wrote a haiku just now

Closing, as it is not a kata issue. Also, why do you have a loop there? You have the return inside it and it won't loop more than once.

Your code currently only works when the list has exactly 3 elements in it.

Try to imagine / picture what would happen if the list had fewer or more than 3 elements.

Can you find a way to rewrite it so it works on lists of any length?