99...9(2003个9)*99...9(2003个9)+199...9(2003个9)
=99..9(2003个9)*99...9(2003个9)++10^2003+99...9(2003个9)
=99..9(2003个9)*(1+99...9(2003个9))+10^2003
=99..9(2003个9)*10^2003+10^2003
=10^2003*(1+99...9(2003个9))
=10^2003+10^2003
=2*10^2003
99...9(2003个9)*99...9(2003个9)+199...9(2003个9)
=99..9(2003个9)*99...9(2003个9)++10^2003+99...9(2003个9)
=99..9(2003个9)*(1+99...9(2003个9))+10^2003
=99..9(2003个9)*10^2003+10^2003
=10^2003*(1+99...9(2003个9))
=10^2003+10^2003
=2*10^2003