@foo = ('a(b(c)d(e(f)g)h)i(j(k)l(m)n)o',
        'a(b(c)d(e(f)g)h)i(j(k)l(m)n)o)');

for (@foo) {
   print "\'$_\' has ";

   while ( s/\([^()]*\)// ){}

   print "un" if /[()]/;
   print "balanced parentheses\n";
}