def output_end(t_start, t_end):
    """print total running time"""
    print('\n' + '-' * 70)
    print('\nTotal elapsed time = {:.2f} seconds.'.format(t_end - t_start))
    art = """
                           .
                          ":"
                        ___:____     |"\\/"|
                      ,'        `.    \\  /
                      |  O        \\___/  |
                    ~^~^~^~^~^~^~^~^~^~^~^~^~
           """
    print(art)
