while (my $job = $jobs->hash) {
my $open = $opens{$job->{problem}, $job->{owner}} // $ct->{start};
my $time = $job->{date} - $open;
while (my $job = $jobs->hash) {
my $open = $opens{$job->{problem}, $job->{owner}} // $ct->{start};
my $time = $job->{date} - $open;