#!perl
use strict;
use warnings;
use 5.12.0;

my $inside = 0;
while ( <> ) {
    chomp;
    my $str = '';
    my @parts = split //;
    $inside = 0;
    for ( @parts ) {
        0 > $inside && $inside++ && warn "WARNING: extra close on line $.\n";
        /\(/ && $inside++ && next;
        /\)/ && $inside-- && next;
        $str .= $_ unless $inside > 0;
    }
    warn "WARNING: Unclosed parenthetical on line $.\n" if $inside;
    say $str;
}