Problem D
Datum — Problem Statistics

Back to problem description

Submissions	10481
Accepted submissions	6111
Submission ratio	58.31%
Authors	5918
Full solves [?]	5680
Full solve Ratio	95.98%

#	User	Runtime	Language	Date
1	Thomas Feld	0.01 s	Bash	2023-04-25 06:59:28
2	Chenzhang Hu	0.01 s	Bash	2023-09-25 15:50:34
3	Will Killian	0.01 s	Bash	2024-04-19 18:55:36
4	Russell Ng	0.01 s	Bash	2025-08-05 17:29:20

#	User	Runtime	Language	Date
1	Pontus Eriksson	0.01 s	C#	2017-04-27 15:46:45
2	Madelyn Reyes	0.01 s	C#	2017-06-03 19:27:29
3	Faisal Rahman	0.01 s	C#	2017-10-31 01:55:35
4	Ziga Staresinic	0.01 s	C#	2017-12-25 15:06:23
5	John Ladera	0.01 s	C#	2018-03-19 04:09:18
6	Klas af Geijerstam	0.02 s	C#	2017-04-11 13:17:05
7	Duelene Olson	0.02 s	C#	2017-04-20 20:41:45
8	Rasmus Brants	0.02 s	C#	2017-04-26 13:32:51
9	Jakub Jagiello	0.02 s	C#	2017-05-09 08:43:53
10	Mauricio Viscarra	0.02 s	C#	2017-05-27 04:44:00

#	User	Runtime	Language	Date
1	Dmytro Bihniak	0.01 s	Common Lisp	2019-08-26 10:45:59
2	John Dandy	0.01 s	Common Lisp	2020-01-25 22:21:52
3	wibi	0.01 s	Common Lisp	2020-08-16 21:52:47
4	David Cawthon	0.02 s	Common Lisp	2019-04-24 23:45:56

#	User	Runtime	Language	Date
1	Emil Jessen	0.04 s	F#	2020-09-24 18:08:44
2	Jacob Harris Cryer Kragh	0.04 s	F#	2022-05-30 18:16:55
3	David Vinje	0.05 s	F#	2022-08-02 16:27:43
4	Elias Illeris Poggi	0.06 s	F#	2025-02-26 16:20:03

#	User	Runtime	Language	Date
1	Ben Hutchinson	0.00 s	Go	2023-10-16 08:46:24
2	Vadim Popolitov	0.00 s	Go	2025-06-02 10:46:26
3	Jimmy Nejtron	0.02 s	Go	2022-12-22 14:54:29
4	Hidden user	0.02 s	Go	2023-01-21 02:14:55
5	Ross O'Sullivan	0.07 s	Go	2018-08-17 14:35:51
6	Alejandro Germain	0.07 s	Go	2018-10-03 17:44:32
7	Eric Martin	0.07 s	Go	2018-12-27 06:32:18
8	Krzysztof Gibuła	0.07 s	Go	2019-01-06 14:24:19
9	Erik Pettersson	0.07 s	Go	2019-04-11 14:19:57
10	Hidden user	0.07 s	Go	2021-12-15 13:09:42

#	User	Runtime	Language	Date
1	Nathaniel Lahn	0.04 s	Java	2025-02-25 02:46:38
2	William Brigham	0.05 s	Java	2017-04-19 01:57:15
3	Pontus Eriksson	0.05 s	Java	2017-04-25 19:49:08
4	Martijn Muijsers	0.05 s	Java	2017-04-28 08:18:40
5	Samuel Klingström	0.05 s	Java	2017-04-29 17:40:04
6	James Black	0.05 s	Java	2017-05-02 00:13:03
7	Rick van Rheenen	0.05 s	Java	2017-05-18 14:37:41
8	Finn Lidbetter	0.05 s	Java	2017-05-18 17:30:59
9	Liam Keliher	0.05 s	Java	2017-06-01 06:04:21
10	Mike Beckers	0.05 s	Java	2017-06-13 11:59:39

#	User	Runtime	Language	Date
1	Hidden user	0.04 s	JavaScript (Node.js)	2024-07-12 03:13:50
2	Ismail Tahiri	0.05 s	JavaScript (Node.js)	2018-07-11 14:23:44
3	Christoffer Karlsson	0.05 s	JavaScript (Node.js)	2018-07-21 13:41:38
4	Carl Sundvall	0.05 s	JavaScript (Node.js)	2018-10-26 08:40:47
5	Dario Delle Donne	0.05 s	JavaScript (Node.js)	2018-12-17 20:47:26
6	Tomáš Necky Necuda	0.05 s	JavaScript (Node.js)	2019-02-05 20:43:22
7	Gurpartap Singh Bhatti	0.05 s	JavaScript (Node.js)	2019-02-16 03:48:06
8	José Lucas	0.05 s	JavaScript (Node.js)	2019-03-06 17:03:52
9	Sander Hellesø	0.05 s	JavaScript (Node.js)	2019-04-14 01:55:31
10	Hidden user	0.05 s	JavaScript (Node.js)	2019-05-30 15:06:10

#	User	Runtime	Language	Date
1	Bjørn Chr. Soltvedt	0.01 s	JavaScript (SpiderMonkey)	2017-04-10 08:39:20
2	Peter Kedemo	0.01 s	JavaScript (SpiderMonkey)	2017-06-04 16:11:30
3	Spencer Smith	0.01 s	JavaScript (SpiderMonkey)	2017-06-06 15:28:55
4	Michael Hjortholt	0.01 s	JavaScript (SpiderMonkey)	2017-07-10 22:25:15
5	Davíð Helgason	0.01 s	JavaScript (SpiderMonkey)	2017-08-07 17:01:22
6	Peter Menyes	0.01 s	JavaScript (SpiderMonkey)	2017-08-08 20:36:19
7	Aletta Géczi	0.01 s	JavaScript (SpiderMonkey)	2017-09-03 10:44:09
8	Martin Jay	0.01 s	JavaScript (SpiderMonkey)	2017-10-31 15:11:22
9	Nicklas Utgaard	0.01 s	JavaScript (SpiderMonkey)	2017-12-03 13:04:37
10	Manish Paudel	0.01 s	JavaScript (SpiderMonkey)	2018-03-09 04:25:12

#	User	Runtime	Language	Date
1	Danny Robinson	0.50 s	Julia	2023-09-01 04:00:45
2	Timothy Gaede	0.53 s	Julia	2024-03-19 10:14:43

#	User	Runtime	Language	Date
1	Vyas Nellutla	0.15 s	Kotlin	2018-10-03 02:19:36
2	Jacob Huebner	0.16 s	Kotlin	2020-03-17 21:12:31
3	Neil Harmon	0.19 s	Kotlin	2019-04-02 09:01:50
4	MisterDerpie	0.19 s	Kotlin	2021-07-02 19:02:48
5	Troy Warmboe	0.21 s	Kotlin	2018-10-20 04:45:43
6	Clinton Walker	0.21 s	Kotlin	2019-09-09 06:11:13
7	Jonathan Soo	0.21 s	Kotlin	2019-10-21 08:44:40
8	Jörgen Andersson	0.21 s	Kotlin	2020-06-29 19:09:59
9	Adam Rankin	0.21 s	Kotlin	2023-05-01 04:15:40
10	Jesper Bech Christensen	0.21 s	Kotlin	2023-09-29 12:04:32

#	User	Runtime	Language	Date
1	Fredrik Eriksson	0.00 s	OCaml	2024-10-17 19:51:40

#	User	Runtime	Language	Date
1	Hidden user	0.00 s	Odin	2025-04-24 19:10:30

#	User	Runtime	Language	Date
1	David Connolly	0.00 s	Pascal	2017-09-04 13:37:49
2	Vova Podkorytov	0.00 s	Pascal	2018-01-03 09:20:16
3	Egor Shchetinin	0.00 s	Pascal	2018-01-15 13:59:21
4	Ingemar Ragnemalm	0.00 s	Pascal	2018-03-01 13:10:05
5	Jiyeon	0.00 s	Pascal	2019-04-12 13:40:24
6	Chan Hok To	0.00 s	Pascal	2020-02-11 12:30:57
7	Huỳnh Minh Lâm	0.00 s	Pascal	2022-09-27 13:54:51

#	User	Runtime	Language	Date
1	Peter Sofronas	0.01 s	PHP	2017-07-13 19:24:59
2	Helbin Grégory	0.01 s	PHP	2020-01-20 12:07:27
3	Renate Fiala-Lundström	0.01 s	PHP	2021-04-15 14:49:11
4	Muhammad Asyraf bin Akop	0.01 s	PHP	2022-05-13 03:05:46
5	Susanne Ragnemalm	0.01 s	PHP	2024-05-12 11:23:14

#	User	Runtime	Language	Date
1	Andriy Zyevakov	0.01 s	Prolog	2017-06-16 18:19:36
2	Hadi Qovaizi	0.01 s	Prolog	2018-06-28 21:57:44
3	Hakan Kjellerstrand	0.02 s	Prolog	2023-01-21 09:58:54

#	User	Runtime	Language	Date
1	Christofer Ohlsson	0.02 s	Python 2	2017-04-06 18:27:55
2	Meher Béjaoui	0.02 s	Python 2	2017-06-01 21:04:45
3	Johan Wind	0.02 s	Python 2	2017-06-03 22:40:15
4	Jeff Robertson	0.02 s	Python 2	2017-08-09 19:10:46
5	Eoin Davey	0.02 s	Python 2	2017-09-08 19:44:27
6	Alex Meed	0.02 s	Python 2	2017-10-27 23:05:32
7	Andrei Stoica	0.02 s	Python 2	2017-11-06 16:05:25
8	Rio Harapan Pangihutan	0.02 s	Python 2	2017-11-17 03:45:02
9	Sigurður Jens Albertsson	0.02 s	Python 2	2017-11-20 21:52:49
10	shrek the ogre lord	0.02 s	Python 2	2017-12-03 06:05:00

#	User	Runtime	Language	Date
1	Robert Welin-Berger	0.02 s	Python 3	2017-04-06 18:01:52
2	Bernhard Kartefla	0.02 s	Python 3	2017-04-07 11:03:09
3	Sebastian Dolan	0.02 s	Python 3	2017-04-07 17:03:37
4	Wayne	0.02 s	Python 3	2017-04-07 18:08:39
5	Ciara Godwin	0.02 s	Python 3	2017-04-07 22:45:23
6	Anthony Clays	0.02 s	Python 3	2017-04-17 10:07:21
7	James Hamm	0.02 s	Python 3	2017-04-25 01:27:53
8	Денис Соболев	0.02 s	Python 3	2017-04-25 09:55:49
9	Joshua Guerin	0.02 s	Python 3	2017-04-26 21:17:56
10	Martin Jackson	0.02 s	Python 3	2017-05-01 17:50:11

#	User	Runtime	Language	Date
1	Hidden user	0.03 s	Ruby	2017-05-07 21:11:33
2	Clifford Owino	0.03 s	Ruby	2017-05-25 04:39:08
3	Mona Dadoun	0.03 s	Ruby	2017-12-30 17:57:57
4	Paul Vinell	0.03 s	Ruby	2018-03-13 12:42:21
5	Omar Al-Khashab	0.04 s	Ruby	2018-04-23 08:20:10
6	Joel Niemelä	0.04 s	Ruby	2018-05-02 03:57:11
7	Jason Cheong-Kee-You	0.04 s	Ruby	2018-05-27 00:48:38
8	Daniel Harder	0.04 s	Ruby	2018-08-31 22:25:28
9	Angelo Ruperti	0.04 s	Ruby	2019-08-14 14:29:50
10	Macdara mac an tSionnaigh	0.04 s	Ruby	2019-09-17 23:57:32

#	User	Runtime	Language	Date
1	Danial Haseeb	0.00 s	Swift	2023-10-09 16:26:23

#	User	Length	Language	Date
1	Russell Ng	28	Bash	2025-08-05 17:29:20
2	Chenzhang Hu	28	Bash	2025-09-12 14:28:11
3	Thomas Feld	29	Bash	2023-09-28 08:06:20
4	Will Killian	30	Bash	2024-04-19 18:59:17

#	User	Length	Language	Date
1	Martin Blom	186	C	2023-09-24 12:46:14
2	Mihir Patel	303	C	2018-01-15 14:51:31
3	Bokor	303	C	2018-05-11 14:07:54
4	Johan Öhlin	318	C	2017-07-03 09:17:47
5	winnie the pooh	320	C	2021-05-29 07:35:41
6	jadrs02	329	C	2020-12-18 11:42:32
7	Jovan Reynardo	340	C	2018-10-19 08:01:28
8	Hidden user	349	C	2019-04-24 08:02:28
9	Romario Putra	358	C	2019-10-20 15:50:17
10	Nguyễn Tiến Đạt	362	C	2019-04-24 12:32:07

#	User	Length	Language	Date
1	Mikael Palokangas	150	C#	2023-01-18 09:56:32
2	Jakub Jagiello	216	C#	2017-05-09 08:43:53
3	李陆屿	233	C#	2018-12-23 10:49:03
4	Klas af Geijerstam	244	C#	2017-04-11 13:17:05
5	Pierre Hébert	264	C#	2017-12-15 17:29:30
6	Lukas Brolin	264	C#	2022-04-04 15:18:07
7	Peter Nordh	274	C#	2018-06-09 20:27:42
8	Stoffe Malmberg	280	C#	2022-12-27 09:52:29
9	Steve Jia	281	C#	2018-08-21 13:32:31
10	Kunwei Zhang	287	C#	2018-02-04 03:28:45

#	User	Length	Language	Date
1	Patrick Jacobs	251	C++	2019-04-02 01:46:59
2	Admasu Abera	251	C++	2019-12-01 19:16:01
3	Richard Putra	253	C++	2018-02-19 04:42:07
4	apd	259	C++	2024-11-08 06:46:45
5	Timotius Jason	267	C++	2021-05-01 16:21:26
6	Basil Semuonov	269	C++	2019-11-27 11:25:50
7	Ritchie Goldwin	277	C++	2018-12-29 14:11:20
8	Ricky Chen	286	C++	2020-05-12 02:47:36
9	Grae Yeandle	289	C++	2017-04-29 15:26:12
10	Jan Livens	291	C++	2017-09-15 12:33:24

#	User	Length	Language	Date
1	John Dandy	293	Common Lisp	2020-01-25 22:21:52
2	David Cawthon	338	Common Lisp	2019-04-24 23:45:56
3	Dmytro Bihniak	372	Common Lisp	2019-08-26 10:45:59
4	wibi	427	Common Lisp	2020-08-16 21:52:47

#	User	Length	Language	Date
1	Jacob Harris Cryer Kragh	167	F#	2022-05-30 18:16:55
2	Emil Jessen	684	F#	2020-09-24 18:08:44
3	Elias Illeris Poggi	745	F#	2025-02-26 16:20:03
4	David Vinje	1199	F#	2022-08-02 16:27:43

#	User	Length	Language	Date
1	Hidden user	199	Go	2021-12-15 13:09:42
2	Samsu Sempena	203	Go	2020-11-06 13:17:34
3	Hidden user	205	Go	2017-12-01 18:56:44
4	Jimmy Nejtron	205	Go	2022-12-22 14:54:29
5	Alejandro Germain	215	Go	2018-10-03 17:44:32
6	Vadim Popolitov	233	Go	2025-06-02 10:46:26
7	Erik Pettersson	240	Go	2019-04-11 14:19:57
8	Kok Dith	243	Go	2021-07-29 16:47:11
9	Ben Hutchinson	245	Go	2023-10-16 08:46:24
10	Andi Baso Annas	362	Go	2020-09-02 03:46:46

#	User	Length	Language	Date
1	John Doe	92	Haskell	2023-05-02 13:54:15
2	Alex Marion	178	Haskell	2024-07-06 03:10:35
3	Daniel Cabral	194	Haskell	2022-02-03 15:47:23
4	Patrick Bahr	289	Haskell	2018-11-24 12:47:06
5	Zach Tschetter	289	Haskell	2021-08-27 23:47:12
6	Llaurence Git	303	Haskell	2018-11-06 10:26:17
7	Tim Put	313	Haskell	2021-04-18 22:20:35
8	Isidro Matos Bellido	321	Haskell	2018-03-31 11:45:38
9	Brent Yorgey	338	Haskell	2017-10-01 15:05:37
10	Jordan McIntyre	344	Haskell	2020-05-17 23:14:34

#	User	Length	Language	Date
1	Chandradhar Gowtham	269	Java	2019-02-28 16:00:07
2	Bryan Wong Wei Heng	310	Java	2019-11-06 11:25:14
3	Bhavpreet Singh Arneja	324	Java	2023-11-07 03:39:36
4	MADHUMITHA K	325	Java	2025-05-02 13:32:21
5	Terry Morris	335	Java	2020-12-18 17:40:02
6	Sergey Jakobsen	348	Java	2020-12-27 15:53:25
7	Robert Slutsky	360	Java	2018-01-25 00:05:36
8	Ryno Botes	362	Java	2025-04-21 22:18:15
9	Raymond Arrington	375	Java	2024-06-17 02:13:34
10	Pranav Addepalli	383	Java	2020-02-10 02:55:50

#	User	Length	Language	Date
1	Vu Van Dung	291	JavaScript (Node.js)	2022-09-14 17:58:56
2	Karim Dridi	327	JavaScript (Node.js)	2022-01-14 14:45:00
3	Emil Larsson	358	JavaScript (Node.js)	2020-06-28 18:40:02
4	Christoffer Karlsson	372	JavaScript (Node.js)	2018-07-21 13:41:38
5	Tomáš Necky Necuda	375	JavaScript (Node.js)	2019-02-05 20:43:22
6	Antoine Bauri	387	JavaScript (Node.js)	2021-02-18 19:56:37
7	Philipp Hergenhahn	387	JavaScript (Node.js)	2025-01-08 14:15:58
8	Ismail Tahiri	439	JavaScript (Node.js)	2018-07-11 14:23:44
9	jai ram	447	JavaScript (Node.js)	2019-12-04 13:38:43
10	Gustav Junedahl	493	JavaScript (Node.js)	2019-11-07 20:44:09

#	User	Length	Language	Date
1	Christian Pilegaard Cederquist	124	JavaScript (SpiderMonkey)	2022-10-31 00:56:28
2	Evan Magill	165	JavaScript (SpiderMonkey)	2024-04-19 03:27:57
3	Bjørn Chr. Soltvedt	181	JavaScript (SpiderMonkey)	2017-04-10 08:39:20
4	Jimmy Gustafsson	222	JavaScript (SpiderMonkey)	2022-06-23 19:37:04
5	Dylan Mcdougall	225	JavaScript (SpiderMonkey)	2019-11-18 18:29:28
6	Bernard Perrin	229	JavaScript (SpiderMonkey)	2019-01-18 19:10:26
7	Nguyễn Mạnh Phúc	236	JavaScript (SpiderMonkey)	2018-07-13 06:23:52
8	Goran Sherko Jawdat	248	JavaScript (SpiderMonkey)	2018-04-25 07:45:13
9	Aletta Géczi	249	JavaScript (SpiderMonkey)	2017-09-03 10:44:09
10	Gabor Varga	259	JavaScript (SpiderMonkey)	2018-03-31 13:34:41

#	User	Length	Language	Date
1	Danny Robinson	159	Julia	2023-09-01 04:00:45
2	Timothy Gaede	515	Julia	2024-03-19 10:14:43

#	User	Length	Language	Date
1	Albert Pala	204	Kotlin	2021-05-27 11:24:38
2	Dmitry Shostak	235	Kotlin	2018-08-28 07:37:01
3	Hamdanil Rasyid	237	Kotlin	2025-03-31 01:51:46
4	Jesper Bech Christensen	260	Kotlin	2023-09-29 12:04:32
5	Stefan Kennedy	269	Kotlin	2017-12-04 18:22:52
6	axl	270	Kotlin	2019-08-05 07:22:21
7	Frangel Hernández Martinez	317	Kotlin	2018-04-25 03:46:27
8	Mark Mathis	332	Kotlin	2018-10-13 01:24:26
9	Alan Pramuk	410	Kotlin	2022-07-29 11:54:57
10	Hidden user	416	Kotlin	2020-03-09 22:37:39

#	User	Length	Language	Date
1	Fredrik Eriksson	628	OCaml	2024-10-17 19:51:40

#	User	Length	Language	Date
1	Hidden user	569	Odin	2025-04-24 19:10:30

#	User	Length	Language	Date
1	Jiyeon	418	Pascal	2019-04-12 13:40:24
2	Ingemar Ragnemalm	431	Pascal	2018-03-01 13:10:05
3	David Connolly	719	Pascal	2017-09-04 13:37:49
4	Egor Shchetinin	1330	Pascal	2018-01-15 13:59:21
5	Huỳnh Minh Lâm	1529	Pascal	2022-09-27 13:54:51
6	Vova Podkorytov	1622	Pascal	2018-01-03 09:20:16
7	Chan Hok To	5944	Pascal	2020-02-11 12:30:57

#	User	Length	Language	Date
1	Renate Fiala-Lundström	94	PHP	2021-04-15 14:49:11
2	Helbin Grégory	122	PHP	2020-01-20 12:07:27
3	Susanne Ragnemalm	155	PHP	2024-05-12 11:23:14
4	Muhammad Asyraf bin Akop	172	PHP	2022-05-13 03:05:46
5	Peter Sofronas	327	PHP	2017-07-13 19:24:59

#	User	Length	Language	Date
1	Andriy Zyevakov	236	Prolog	2017-06-16 18:19:36
2	Hakan Kjellerstrand	263	Prolog	2023-01-21 09:58:54
3	Hadi Qovaizi	1634	Prolog	2020-06-09 01:33:56

#	User	Length	Language	Date
1	Marc Lozier	112	Python 2	2019-07-28 17:42:11
2	Simon Vestin	115	Python 2	2019-01-17 11:31:30
3	Oscar Melin	115	Python 2	2019-07-23 18:04:15
4	Wendirad Demelash	120	Python 2	2019-03-14 15:23:49
5	Hidden user	120	Python 2	2019-11-24 00:36:51
6	Çağdaş Öztekin	123	Python 2	2017-08-29 04:20:29
7	Gustavo Ribeiro	124	Python 2	2018-09-22 00:56:14
8	Kuenzang Choden	125	Python 2	2019-05-09 18:43:29
9	Frederik Højholt	140	Python 2	2017-10-13 17:14:20
10	Johan Lyts	143	Python 2	2019-03-07 21:00:02

#	User	Length	Language	Date
1	Will Killian	85	Python 3	2024-04-19 16:39:49
2	Lawry Sorenson	86	Python 3	2023-01-12 23:54:03
3	Clement Oh	86	Python 3	2023-05-18 14:07:35
4	Tommi Järvenpää	88	Python 3	2024-03-19 06:43:23
5	Josh Taylor	89	Python 3	2022-09-30 15:41:34
6	Andre Josiah Budianto	92	Python 3	2023-01-03 07:01:06
7	Meng Siong Hwee	92	Python 3	2023-01-07 15:44:30
8	Adam Levav	92	Python 3	2023-01-18 23:13:46
9	Thomas Delapart	92	Python 3	2024-01-18 08:37:07
10	Clavianus Juneardo	95	Python 3	2018-06-21 18:01:05

#	User	Length	Language	Date
1	Thomas Feld	47	Ruby	2023-01-04 14:38:44
2	dick move	64	Ruby	2022-12-06 17:50:42
3	Abolfazl Gol	85	Ruby	2018-07-29 10:19:37
4	Régis Hanol	86	Ruby	2022-01-06 22:29:47
5	Olivia Bednar	97	Ruby	2021-11-05 05:34:09
6	Eugen Neagoe	101	Ruby	2023-05-05 13:42:36
7	John Ray Clementz A. Servo	101	Ruby	2025-08-06 11:29:56
8	Lim Ming Yean	102	Ruby	2018-11-14 07:03:58
9	Daniel Harder	104	Ruby	2018-08-31 22:25:28
10	Jason Cheong-Kee-You	109	Ruby	2018-05-27 00:48:38

#	User	Length	Language	Date
1	Vincent Lagerros	354	Rust	2025-01-17 09:21:27
2	Emil Dichmann	462	Rust	2025-09-21 10:55:47
3	Pankajkumar Patro	584	Rust	2024-07-18 19:41:31
4	Florent Haratyk	602	Rust	2019-03-30 19:26:54
5	Joe Blower	627	Rust	2025-06-06 01:35:44
6	Hovig Manjikian	668	Rust	2019-12-28 20:19:46
7	Andriy Semenistiy	722	Rust	2021-02-13 14:32:10
8	Peter Hrvola	724	Rust	2019-04-12 13:58:11
9	Phoxy Tr0ut	731	Rust	2025-08-10 23:00:37
10	Michael Vesterli	838	Rust	2019-04-12 14:36:03

#	User	Length	Language	Date
1	Danial Haseeb	613	Swift	2023-10-09 16:26:23

Solution running time distribution