def format_list(my_list):
    length_list = len(my_list)
    my_list = my_list[range(length_list)][::2]
    last_one = my_list.pop()
    my_list = ', '.join(my_list)
    last_one = 'and ' + last_one
    my_list = my_list + [last_one]
    return(my_list)