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

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

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

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

$ perl 892828_c.pl
(0-1999999), (1999999-3999998), (3999998-5999997), (5999997-7999996), (7999996-9999995)