1-2/3-1/6-1/12-1/24-1/48-……1/768
=1/3-1/6-1/12-1/24-1/48-……1/768
=1/6-1/12-1/24-1/48-……1/768
=1/12-1/24-1/48-……1/768
=1/24-1/48-……1/768
=1/768