def parents(d, name):
    return d[name]


def grandparents(d, name):
    grandpar = []
    for par in parents(d, name):
        if par in d.keys():
            grandpar += parents(d, par)
    return grandpar


def find_name(dictionary, value):
    """
        Function to get keys from the dictionary by value

        Input:

        dictionary - dict
        value - any type of value in this dict

        Output:

        names - finded keys
    """
    names = []
    for name, val in dictionary.items():
        if val == value:
            names.append(name)
    return names


def sibling(d, name):
    par = parents(d, name)
    sibl = find_name(d, par)
    sibl.remove(name)
    return sibl


def children(d, name):
    chil = []
    for key, val in d.items():
        if name in val:
            chil.append(key)
    return chil


def grandchildren(d, name):
    grandchil = []
    chil = children(d, name)
    for key, val in d.items():
        for c in chil:
            if c in val:
                grandchil.append(key)
    return(grandchil)