def add_to_start(solutions, add_num):
    """The current function gets a list of lists and number. The function
    will add all sub-lists into an updated list with each sub-list added
    at the beginning of the list the number the function is gets"""
    final_list = []
    if solutions is None:
        return None
    for solution in solutions:
        final_list.append([add_num] + solution)
    return final_list