IGNORE
Problem has been resolved by myself. Apparently two cities can connect multiple times directly. I had assumed this to be a mistake, but it is not. The specific line connects C-K two times, meaning there is a cycle. Sorry for the inconvenience :D

Hi guys, could you verify that line 19 does not contain any cycles?
Doing this task I had all but the 19th line correctly computed. Checking it manually I can't detect any cycles, not even by drawing it in a graph maker.

Otherwise, the checker might have some sort of problem with that specific set.

Refer to http://www.codeabbey.com/index/task_view/cycles-detection for problem description.

Expected answer:
0 0 0 1 0 0 0 1 0 0 1 1 0 0 1 0 1 1 1 1 1 0 0 0 0 0 1 0
My answer:
0 0 0 1 0 0 0 1 0 0 1 1 0 0 1 0 1 1 0 1 1 0 0 0 0 0 1 0

28
1: 9 L-D W-D Z-D C-D H-C K-W U-C R-L B-K
2: 19 I-Q O-Q J-O B-O R-I M-Q V-I Y-V H-I A-R P-A S-H Z-P T-Y L-S F-L N-M K-Q E-O
3: 18 S-A U-S J-U R-S K-A I-A D-S G-D L-I V-R H-J P-H E-D Q-R T-E X-G N-I O-J
4: 15 O-Q I-Q P-I U-P E-U K-E D-E A-I W-Q N-I B-W M-D T-U Y-U A-D
5: 12 S-C B-S A-B G-B Y-S R-Y P-C E-P J-Y K-A W-Y Z-A
6: 19 F-V B-F W-V T-B Y-V X-F J-V O-J U-W D-T P-X S-T C-Y Q-P R-Q K-S G-S M-V I-K
7: 7 J-Q L-Q A-Q U-L K-A Y-K D-J
8: 10 B-H V-H G-H S-H R-B Q-G U-G N-R F-U V-S
9: 20 T-K G-K D-T X-T W-X Z-W J-X O-Z B-D M-D S-Z L-S Q-O V-T F-W U-D P-X R-F E-D A-L
10: 12 J-O U-J V-J Q-J I-O A-I X-I H-V Y-Q F-V M-A W-Q
11: 17 D-Z F-D A-Z Y-F Q-Y R-A C-A G-A U-C W-C E-A N-E L-F H-Q T-N K-F K-U
12: 20 F-A N-F C-N K-A T-F Z-N G-C Y-A L-N W-A H-W J-W R-H P-F X-N Q-A D-P O-H M-R J-G
13: 18 E-K Z-K C-E V-E A-C B-V P-C M-E I-C X-I J-X L-V U-X T-M S-B F-A H-K Q-X
14: 20 F-T B-T H-B X-F P-T E-X J-H N-J S-E D-X I-E V-J U-I C-T K-I Z-C Q-X M-C R-E L-T
15: 7 O-E I-E A-E L-E Y-I N-L L-I
16: 6 C-J V-C M-V I-V U-I Q-C
17: 15 E-B F-E O-E D-E S-B A-D H-A M-F X-M Y-X Q-D C-Y J-D K-X B-F
18: 9 O-B N-B D-N E-B S-N R-S H-O Q-O Q-D
19: 18 K-X Y-X T-X I-X C-K J-Y M-C S-X H-I Z-K U-I W-S B-S V-C L-W O-B F-I C-K
20: 23 Z-L F-Z U-F H-L W-U B-L C-Z A-U X-Z Q-L P-C E-C O-P D-E M-E N-H Y-F G-Z S-G J-X R-D T-L A-P
21: 22 S-U J-U C-S V-S L-J Z-J B-V F-J H-S R-L D-H Y-H N-S A-L W-B E-Z X-E K-B P-J O-N I-B U-V
22: 14 U-K W-K M-K R-U D-M G-D A-M N-A T-U E-T P-R C-R J-M S-C
23: 11 O-K I-K H-O E-H M-O P-I Y-P N-M R-E X-H D-I
24: 15 S-C W-C J-W U-J E-S Y-E L-Y T-U R-J H-U P-C G-C B-U A-S Z-S
25: 18 X-Y M-Y E-M K-E G-X A-G W-A H-W F-K U-E I-G D-G R-K Q-D J-X N-F L-N V-J
26: 9 V-B T-B P-B Z-V I-T S-Z O-P E-Z C-S
27: 17 O-P U-P F-P J-P E-P R-P Q-O W-O H-Q Y-J K-Q M-F S-W V-K L-E B-M V-S
28: 14 F-B S-F G-F Z-F T-G R-F Q-Z I-T Y-G C-T V-I W-V L-I K-W