read_file(Stream, []) :-
    at_end_of_stream(Stream).

read_file(Stream, [X|L]) :-
    \+ at_end_of_stream(Stream),
    read_line_to_codes(Stream, C),
    atom_chars(A, C),
    read_file(Stream, L),
    atom_number(A, X).

main :-
    open('../input/01', read, Stream),
    read_file(Stream, Lines), !,
    close(Stream),
    step(Lines, N),
    print(N).

step([], 0).
step([A|Tail], B) :-
    step_(A, Tail, B).

step_(_, [], 0).
step_(A, [B|Tail], Res) :-
    A < B,
    step_(B, Tail, TailRes),
    Res is TailRes + 1.
step_(A, [B|Tail], Res) :-
    A >= B,
    step_(B, Tail, Res).