#!/usr/bin/perl
use strict;
use warnings;
use List::Util qw(reduce);

my ($M, $N) = (9999997,5);

my $ranges = reduce {
                [ @$a, [ $$a[-1][1], $b] ]
            } [ [ 0, 1 ] ], map { $_*int($M/$N) } 0 .. $N;

print join(", ", map { "(" . join("-",@{$_}).")" } @$ranges), "\n";

$ perl 892828_d.pl
Name "main::b" used only once: possible typo at 892828_d.pl line 10.
(0-1), (1-0), (0-1999999), (1999999-3999998), (3999998-5999997), (5999997-7999996), (7999996-9999995)