39887-399900
23-900
8000-10000
50000-1000500
...
and so on ...

##</code><code>##

0-22
901-7999
10001-39886
1000501-100000000
##</code><code>##

my @v = grep{my $x = $_; not grep{$x == $_}(100..200)}(1..1000);
my @z = grep{my $x = $_; not grep{$x == $_}(170..350)}@v;