sub add(){
	($_[0]+$_[1])=~?^e??return$&:
	(($,,$:)=reverse(sort(@_)));
	$,?1:($,='0');$:?1:($:='0');
	for(;$:;(($^=~/(\d)(\d?)/)&&
	($2ne''))?(($;=$1)&&($_.=$2)
	):(($_.=$^)&&($;=0))){$:=~##
	/\d$/?($:,$-)=($`,$&):$-=0;
	$,=~/\d$/?($,,$=)=($`,$&):$=
	=0;$^=$=+$-+$;}$;?((($,=~?\d$?
	)?($;+=$&)&&($;.=reverse#$&=3
	$`):0)?1:($_=reverse$_.$;#
	)):($a=reverse$_.reverse$,)
}

##</code><code>##

$a = '11838471545206609368';
$b = '28664024970105317669';
print add($a,$b);