Used data (length=23):
2rrxceodyetwxzzsky683e7
Using 2..12 rails, offset=0:
2/0: 2xrzrzxsckeyo6d8y3eet7w
3/0: 2oydry6ert8wxx3zczesek7
4/0: 2cw8xeroz3zdrysekexty76
5/0: 2xyz3secretkeywordx678z
6/0: 2xyzye6zecrets873kwordx
7/0: 2reezye6ztoxrcdws873kxy
8/0: 2reywzye6sxeoxrcdtzk873
9/0: 2reywzy37e6sxeoxrcdtzk8
10/0: 2reywzk637e8ysxeoxrcdtz
11/0: 2reytxzk637e8yszweoxrcd
12/0: 2rcoytxzk637e8yszwedexr