[perl] 중첩 괄호 제거하기

#!/usr/bin/perl -w

#

$a = "123(ad(f(d(z(a(e))))))456";

$b = "123(adfd)456";

$c = "123(ad)4(fd)56";

$NesteD = qr/ \(( [^()] | (??{ $NesteD }) )* \) /x ;

$a =~ s/$NesteD//gx;

$b =~ s/$NesteD//gx;

$c =~ s/$NesteD//gx;

print "$a\n$b\n$c\n";