def get_db_syllable_side(node, matcher):
    """
    Get which side is suitable according to syllable matching.
    This function expect node to have both syllable neighbours.
    Return minus int if char node should be added to left neighbour,
    plus int if to right,
    0 if not determined.
    """

    if node.prev.syllable is None or node.next.syllable is None:
        raise Exception('Char node does not have both syllable neighbours')

    left_opt_sylls = node.prev.syllable.left_neighbours(node) + node.next.syllable.right_neighbours()
    right_opt_sylls = node.prev.syllable.left_neighbours() + node.next.syllable.right_neighbours(node)

    left_score = matcher.syllable_concord(left_opt_sylls)
    right_score = matcher.syllable_concord(right_opt_sylls)

    return right_score - left_score