>       ┏━┯━┯━┯━┯━┯━┯━┯━┓
>       ┃　│　│　│　│　│　│　│　┃
>       ┠─┼─┼─┼─┼─┼─┼─┼─┨
>       ┃　│　│　│　│　│　│　│　┃
>       ┠─┼─┼─┼─┼─┼─┼─┼─┨
>       ┃　│　│　│　│　│　│　│　┃
>       ┠─┼─┼─┼─┼─┼─┼─┼─┨
>       ┃　│　│　│○│●│　│　│　┃
>       ┠─┼─┼─┼─┼─┼─┼─┼─┨
>       ┃　│　│　│●│●│●│　│　┃
>       ┠─┼─┼─┼─┼─┼─┼─┼─┨
>       ┃　│　│　│　│　│　│　│　┃
>       ┠─┼─┼─┼─┼─┼─┼─┼─┨
>       ┃　│　│　│　│　│　│　│　┃
>       ┠─┼─┼─┼─┼─┼─┼─┼─┨
>       ┃　│　│　│　│　│　│　│　┃
>       ┗━┷━┷━┷━┷━┷━┷━┷━┛


参考：2002/01/11(金)18時21分57秒