[chris@pineapple ranges-892828]$ perl ranges -M=9 -N=1
 0 : from       0 to       9 (     10)
[chris@pineapple ranges-892828]$ perl ranges -M=9 -N=2
 0 : from       0 to       4 (      5)
 1 : from       5 to       9 (      5)
[chris@pineapple ranges-892828]$ perl ranges -M=9 -N=3
 0 : from       0 to       2 (      3)
 1 : from       3 to       5 (      3)
 2 : from       6 to       9 (      4)
[chris@pineapple ranges-892828]$ perl ranges -M=9 -N=4
 0 : from       0 to       1 (      2)
 1 : from       2 to       4 (      3)
 2 : from       5 to       6 (      2)
 3 : from       7 to       9 (      3)
[chris@pineapple ranges-892828]$ perl ranges -M=9 -N=5
 0 : from       0 to       1 (      2)
 1 : from       2 to       3 (      2)
 2 : from       4 to       5 (      2)
 3 : from       6 to       7 (      2)
 4 : from       8 to       9 (      2)
[chris@pineapple ranges-892828]$ perl ranges -M=9 -N=6
 0 : from       0 to       0 (      1)
 1 : from       1 to       2 (      2)
 2 : from       3 to       4 (      2)
 3 : from       5 to       5 (      1)
 4 : from       6 to       7 (      2)
 5 : from       8 to       9 (      2)
[chris@pineapple ranges-892828]$ perl ranges -M=4 -N=0
N < 1 makes no sense.

[chris@pineapple ranges-892828]$ perl ranges -M=4 -N=1
 0 : from       0 to       4 (      5)
[chris@pineapple ranges-892828]$ perl ranges -M=4 -N=2
 0 : from       0 to       1 (      2)
 1 : from       2 to       4 (      3)
[chris@pineapple ranges-892828]$ perl ranges -M=4 -N=3
 0 : from       0 to       0 (      1)
 1 : from       1 to       2 (      2)
 2 : from       3 to       4 (      2)
[chris@pineapple ranges-892828]$ perl ranges -M=4 -N=4
 0 : from       0 to       0 (      1)
 1 : from       1 to       1 (      1)
 2 : from       2 to       2 (      1)
 3 : from       3 to       4 (      2)
[chris@pineapple ranges-892828]$ perl ranges -M=4 -N=5
M must be equal to N or larger than N.