use strict;
use warnings;

my @data = <DATA>;
my $cutpos = (map {$data[$_] eq "{\n" ? $_ : ()} 0 .. $#data)[-1];
defined $cutpos  or  die "Keine Klammer in der Datei\n";
$#data = $cutpos - 1;
print @data;

__DATA__
12
i0
{
xo
46
{
28
98