11111111...1(2008个1)×999999999...9(2008个9)
=11111111...1(2008个1)×(10000000...(2008个0)-1)
=1111111...100000...0(2008个1,2008个0)-11111111...1(2008个1)
=11111...1(2007个1)0888888.....(2007个8)9
=11111111...1(2008个1)×(10000...(2008个0)-1)
=111111...1000...00(2008个1,2008个0)-1111...111(2008个1)
=11111...10888...89(2007个1,2007个8)