# Ponder This

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## July 2019 - Challenge

This month's challenge is by Hugo Pfoertner. (Thanks!)

A non-intersecting knight's cycle is a closed tour made of legal moves of a chess knight on a rectangular board of size mXn, such that the straight lines connecting consecutively visited fields make a simple polygon of an enclosed area A.
Find two non-intersecting knight's cycles of length 14 on boards of size \le 40 such that the difference between their areas is at least 7.

As an example, there are two non-intersecting knight's cycles of length 4 on boards of size \le 16 such that the difference between their areas is 1:
The first has an area of 3 on 4x4 board: a1 c2 d4 b3 a1
and the second has an area of 4 on 3x5 board: c1 e2 c3 a2 c1.

Submit your solution as two lines of 15 visited fields (start=end) using algebraic chess notation as we used above.

We will post the names of those who submit a correct, original solution! If you don't want your name posted then please include such a statement in your submission!

We invite visitors to our website to submit an elegant solution. Send your submission to the ponder@il.ibm.com.

If you have any problems you think we might enjoy, please send them in. All replies should be sent to: ponder@il.ibm.com

Challenge: 28/06/2019 @ 12:00 PM EST
Solution: 03/08/2019 @ 12:00 PM EST
List Updated: 05/08/2019 @ 12:00 PM EST

Bert Dobbelaere (30/06/2019 05:02 PM IDT)
Daniel Chong Jyh Tar (30/06/2019 07:45 PM IDT)
Thomas HUET (30/06/2019 08:11 PM IDT)
Deron Stewart (30/06/2019 08:12 PM IDT)
Kang Jin Cho (30/06/2019 09:06 PM IDT)
Todd Will (01/07/2019 12:02 AM IDT)
Alper Halbutogullari (01/07/2019 12:39 AM IDT)
Florian Fischer (01/07/2019 12:54 AM IDT)
Reiner Martin (01/07/2019 01:46 AM IDT)
Gary M. Gerken (01/07/2019 03:15 AM IDT)
Muhammed Halbutogullari (01/07/2019 11:40 AM IDT)
Jingran Lin (01/07/2019 11:47 PM IDT)
Siegmar Szlavik (01/07/2019 11:54 PM IDT)
Calvin Pozderac (02/07/2019 01:22 AM IDT)
Rogerio Ponce da Silva (02/07/2019 10:00 AM IDT)
Kevin Bauer (02/07/2019 04:03 PM IDT)
Guillaume Escamocher (02/07/2019 04:07 PM IDT)
George Wahid (02/07/2019 04:12 PM IDT)
Nico Elayda (02/07/2019 09:46 PM IDT)
Mark Mammel (02/07/2019 10:19 PM IDT)
Daniel Bitin (02/07/2019 11:56 PM IDT)
Eden Saig (03/07/2019 09:40 AM IDT)
Vladimir Volevich (03/07/2019 01:01 PM IDT)
Haye Chan (03/07/2019 03:04 PM IDT)
Victor Chang (03/07/2019 06:59 PM IDT)
Stanislav Grudnitskiy (04/07/2019 12:46 AM IDT)
Nigel Brumpton (04/07/2019 01:07 AM IDT)
Jordan Rinder (04/07/2019 04:29 AM IDT)
Chris Shannon (04/07/2019 07:52 AM IDT)
Mathias Schenker (04/07/2019 09:33 AM IDT)
James Dow Allen (04/07/2019 05:18 PM IDT)
Alex Fleischer (04/07/2019 06:40 PM IDT)
Jeffrey Roh (04/07/2019 09:04 PM IDT)
Muralidhar Seshadri (05/07/2019 10:16 PM IDT)
Adrienne Stanley (06/07/2019 12:32 AM IDT)
Pål Hermunn Johansen (06/07/2019 01:56 AM IDT)
JJ Rabeyrin This IBM (06/07/2019 03:31 AM IDT)
Keith Kaplan (06/07/2019 05:23 AM IDT)
Tom Chen (06/07/2019 12:06 PM IDT)
Graham Hemsley (06/07/2019 12:58 PM IDT)
Andrew Lee (06/07/2019 03:22 PM IDT)
Jimmy Waters (06/07/2019 06:23 PM IDT)
Lorenz Reichel (06/07/2019 11:33 PM IDT)
Nyles Heise (06/07/2019 11:51 PM IDT)
Min Jung Kim (07/07/2019 06:59 PM IDT)
Joonsoo Lee (07/07/2019 08:15 PM IDT)
Francisco Couzo (08/07/2019 03:59 AM IDT)
John Goh Choo Ern (08/07/2019 08:41 AM IDT)
Andreas Stiller (08/07/2019 03:08 PM IDT)
Michael Liepelt (08/07/2019 08:30 PM IDT)
Evert van Dijken (08/07/2019 09:05 PM IDT)
Karl D’Souza (09/07/2019 03:24 AM IDT)
Ralf Jonas (09/07/2019 09:54 AM IDT)
Amos Guler (09/07/2019 03:53 PM IDT)
Jiho Lee (09/07/2019 07:04 PM IDT)
Gert H. Schlenker (10/07/2019 01:43 PM IDT)
Clive Tong (10/07/2019 02:33 PM IDT)
Marco Bellocchi (10/07/2019 04:48 PM IDT)
Dieter Beckerle (11/07/2019 05:29 AM IDT)
Harald Bögeholz (11/07/2019 11:57 AM IDT)
Larry Kearney (13/07/2019 02:20 AM IDT)
Keith Schneider (14/07/2019 02:30 AM IDT)
Fabio Michele Negroni (14/07/2019 09:23 AM IDT)
Robert Lang (14/07/2019 01:30 PM IDT)
John Tromp (14/07/2019 03:28 PM IDT)
Kristian Kiradjiev (15/07/2019 01:55 AM IDT)
Reda Kebbaj (15/07/2019 03:16 AM IDT)
Sri Mallikarjun J (15/07/2019 06:20 AM IDT)
Christian Pfaffenzeller (16/07/2019 12:40 PM IDT)
David Friedman (17/07/2019 06:43 AM IDT)
Vincent Beaud (17/07/2019 04:04 PM IDT)
Charles Joscelyne (17/07/2019 06:08 PM IDT)
Bin Liu (17/07/2019 07:07 PM IDT)
Wolfgang Glas (18/07/2019 04:35 PM IDT)
Nis Jørgensen (19/07/2019 03:00 PM IDT)
Erik Wünstel (19/07/2019 03:59 PM IDT)
Tom Harley (20/07/2019 07:35 PM IDT)
David Greer (20/07/2019 09:24 PM IDT)
Andy Greig (21/07/2019 06:06 PM IDT)
Bryce Fore (21/07/2019 09:12 PM IDT)
Jacoby Jaeger (22/07/2019 07:21 AM IDT)
Rustam Salikhov (22/07/2019 11:21 AM IDT)
Tom Sirgedas (23/07/2019 01:48 AM IDT)
Sanandan Swaminathan (23/07/2019 10:11 AM IDT)
Doug Miller (27/07/2019 07:17 AM IDT)
Oscar Volpatti (27/07/2019 04:33 PM IDT)
Motty Porat (27/07/2019 10:55 PM IDT)
Albert Stadler (29/07/2019 06:36 PM IDT)
Anna Silenchuk (30/07/2019 03:40 PM IDT)
Michael Čermák (31/07/2019 12:00 AM IDT)
Xiao Liu (31/07/2019 09:41 AM IDT)
Radu-Alexandru Todor (01/08/2019 02:26 AM IDT)
Armin Krauss (01/08/2019 05:27 PM IDT)
Shouky Dan & Tamir Ganor (04/08/2019 03:53 PM IDT)
Li Li (05/08/2019 07:49 AM IDT)