my %pids = ();
for my $line (@lines) {
  if ($line =~ /Beginne.*pid=(\d+)/) {
    $pids{$1}++;
  }
  elsif ($line =~ /Beende.*pid=(\d+)/) {
    $pids{$1}--;
  }
}

for my $uebrig_pid (keys %pids) {
 say $pids{$uebrig_pid} if $pids{$uebrig_pid} > 0;
}