[ 6:17:58.02] C:\test>ranges -M=20 -N=3
 0 : from       0 to       6 (      7)
 1 : from       7 to      13 (      7)
 2 : from      14 to      20 (      7)
========================================
                                   21

[ 7:10:34.53] C:\test>ranges -M=20 -N=2
 0 : from       0 to       9 (     10)
 1 : from      10 to      20 (     11)
========================================
                                   21

[ 7:11:36.69] C:\test>ranges -M=20 -N=1
 0 : from       0 to      20 (     21)
========================================
                                   21