(1/2+1/3+……+1/1997)(1+1/2+……1/1996)-(1+1/2+……+1/1997)(1/2+1/3+……+1/1996)=+C,d;R3}0E'U7{3j8H/s2a6J6R*O0x.U'c4T7V/@+q
算式:提示7|:]3{(o)~6j4t9D2a6J6R*O0x.U'c4T7V/@+q