def get_variable_indices(atom):
    """
    Gets the indexes of the variables in the atom.

    :param atom: the atom
    :type atom: Atom
    :return: the indices of the variables
    :rtype: list[int]
    """
    indexes = []
    for i in range(atom.arity()):
        if not atom.terms[i].is_constant():
            indexes.append(i)

    return indexes