def eparent(node):
    """
    Return an effective parent for the given node.

    The rule for the effective parent - when the current node A has a deprel 'conj' to its parent B,
    return  B.parent, otherwise return A.parent.

    :param node: An input node.
    :return: An effective parent.
    :rtype: udapi.core.node.Node

    """
    if node.deprel == 'conj':
        return node.parent.parent
    return node.parent
