--- modulo(other)

    self  other ǳä; m ֤ޤ(divmod )

     m  other Ʊ(ޤϥ)Ǥ
    Ĥޤ
    * other > 0 ΤȤ  0 <= m < other
    * other < 0 ΤȤ other < m <= 0
    Ȥʤޤ

    Υ᥽åɤϡ᥽å % θƤӽФȤƤޤ
    (Ĥޤꡢ% ƱǤ)

