9999*9999*+19999=100000000
(10000-1)*(10000-1)+19999
=100000000-10000-10000+1+19999
=100000000-10000-10000+20000
=100000000-200000+20000
=100000000
9999*9999*+19999=100000000
(10000-1)*(10000-1)+19999
=100000000-10000-10000+1+19999
=100000000-10000-10000+20000
=100000000-200000+20000
=100000000