$n=<>;
for(<>){
	($a,$b)=glob;
	push@a,$a; $sa+=$a;
	push@b,$b; $sb+=$b;
}
($a)=sort{$b-$a}@a;
($b)=sort{$b-$a}@b;
$mina=$$a*2-$sa; $mina=0 if $mina<0; $sa-=$mina-1;
$minb=$$b*2-$sb; $minb=0 if $minb<0; $sb-=$minb-1;
print $sa<$sb?$sa:$sb;