Lungime

maxim([MAX], MAX).
maxim([Head|Tail], MAX) :-
    maxim(Tail, MAX1),
    Head > MAX1,
    MAX is Head.
maxim([Head|Tail], MAX) :-
    maxim(Tail, MAX1),
    MAX1 >= Head,
    MAX is MAX1.


transform([], []).
transform([Head1|Tail1], [Head2|Tail2]) :-
    atom_chars(Head1, List1),
    length(List1, Head2),
    transform(Tail1, Tail2).

lungime(List, Max) :-
    transform(List, List2),
    maxim(List2, Max).