def get_piece_to_drop(params):
    # pieces_in_danger should be a list
    pieces_in_danger = get_pieces_in_danger(...params)

    # for each piece in pieces_in_danger match the state of the
    # game/board after it (the piece) has been removed. On all the states Si
    # found via the previous mapping, calculate the image of Si by F
    # (utility function) then choose the one or one that minimise F.
    states_after_dropping_piece = []
    for piece in pieces_in_danger:
        # must implement drop_piece first
        # drop_piece(...) put None into the pieces cellules and increment/update
        # the actuelle payer captured_pieces.
        states_after_dropping_piece.append(drop_piece(...params, piece)):

    utility_values = []
    for state in states:
        utility_values.append(compute_utilty(state)) # for ennemy cause it is her tour.

    # we have now to get the index idx of utility_values minimun, which will help use
    # retrieve the best droppable piece doing pieces_in_danger[idx]
    # I assume that the such function helping us to get idx is
    # get_index_of(value, tab_of_values_in_which_to_search)
    idx = get_index_of(min(utility_values), utility)
    return pieces_in_danger[idx]



def get_pieces_in_danger(...params):
    # it seems like we already have function doing this job