1: (4, 6, 9, 14, 15)
2: (5, 6, 10, 15, 17)
3: (4, 5, 6, 9, 11, 20)
4: (1, 3, 6, 18)
5: (2, 3, 6, 7, 14, 17, 18)
6: (1, 2, 3, 4, 5, 7, 11, 14, 15)
7: (5, 6, 9, 14)
8: (9, 13, 16, 17)
9: (1, 3, 7, 8, 12, 15, 17, 19)
10: (2, 12, 17)
11: (3, 6, 14, 19)
12: (9, 10)
13: (8, 18)
14: (1, 5, 6, 7, 11, 17, 18)
15: (1, 2, 6, 9, 16, 18, 19)
16: (8, 15)
17: (2, 5, 8, 9, 10, 14, 18, 19)
18: (4, 5, 13, 14, 15, 17, 20)
19: (9, 11, 15, 17)
20: (3, 18)

The distance from 4 to 19 is 3
A shortest 4-19 path is: (4, 1, 9, 19)

The distance from 9 to 7 is 1
A shortest 9-7 path is: (9, 7)

The distance from 19 to 6 is 2
A shortest 19-6 path is: (19, 11, 6)

The distance from 15 to 7 is 2
A shortest 15-7 path is: (15, 6, 7)

The distance from 6 to 12 is 3
A shortest 6-12 path is: (6, 1, 9, 12)

The distance from 2 to 5 is 1
A shortest 2-5 path is: (2, 5)

The distance from 18 to 16 is 2
A shortest 18-16 path is: (18, 15, 16)

The distance from 7 to 6 is 1
A shortest 7-6 path is: (7, 6)

The distance from 6 to 2 is 1
A shortest 6-2 path is: (6, 2)

The distance from 15 to 16 is 1
A shortest 15-16 path is: (15, 16)

The distance from 9 to 12 is 1
A shortest 9-12 path is: (9, 12)

The distance from 17 to 14 is 1
A shortest 17-14 path is: (17, 14)

The distance from 12 to 6 is 3
A shortest 12-6 path is: (12, 9, 1, 6)

The distance from 4 to 5 is 2
A shortest 4-5 path is: (4, 3, 5)

The distance from 15 to 8 is 2
A shortest 15-8 path is: (15, 9, 8)

The distance from 15 to 17 is 2
A shortest 15-17 path is: (15, 2, 17)

The distance from 14 to 7 is 1
A shortest 14-7 path is: (14, 7)

The distance from 10 to 13 is 3
A shortest 10-13 path is: (10, 17, 8, 13)

The distance from 16 to 8 is 1
A shortest 16-8 path is: (16, 8)

The distance from 3 to 14 is 2
A shortest 3-14 path is: (3, 5, 14)

The distance from 11 to 18 is 2
A shortest 11-18 path is: (11, 14, 18)

The distance from 2 to 17 is 1
A shortest 2-17 path is: (2, 17)

The distance from 1 to 2 is 2
A shortest 1-2 path is: (1, 6, 2)

The distance from 12 to 19 is 2
A shortest 12-19 path is: (12, 9, 19)

The distance from 10 to 11 is 3
A shortest 10-11 path is: (10, 2, 6, 11)

The distance from 13 to 17 is 2
A shortest 13-17 path is: (13, 8, 17)

The distance from 8 to 11 is 3
A shortest 8-11 path is: (8, 9, 3, 11)

The distance from 20 to 17 is 2
A shortest 20-17 path is: (20, 18, 17)

The distance from 15 to 11 is 2
A shortest 15-11 path is: (15, 6, 11)

The distance from 18 to 6 is 2
A shortest 18-6 path is: (18, 4, 6)

The distance from 11 to 9 is 2
A shortest 11-9 path is: (11, 3, 9)

The distance from 15 to 20 is 2
A shortest 15-20 path is: (15, 18, 20)

The distance from 13 to 6 is 3
A shortest 13-6 path is: (13, 18, 4, 6)

The distance from 16 to 3 is 3
A shortest 16-3 path is: (16, 8, 9, 3)

The distance from 20 to 7 is 3
A shortest 20-7 path is: (20, 3, 5, 7)

The distance from 14 to 6 is 1
A shortest 14-6 path is: (14, 6)

The distance from 13 to 19 is 3
A shortest 13-19 path is: (13, 8, 9, 19)

The distance from 2 to 17 is 1
A shortest 2-17 path is: (2, 17)

The distance from 14 to 16 is 3
A shortest 14-16 path is: (14, 1, 15, 16)

The distance from 10 to 5 is 2
A shortest 10-5 path is: (10, 2, 5)

The distance from 4 to 17 is 2
A shortest 4-17 path is: (4, 18, 17)

The distance from 1 to 12 is 2
A shortest 1-12 path is: (1, 9, 12)

The distance from 15 to 1 is 1
A shortest 15-1 path is: (15, 1)

The distance from 12 to 20 is 3
A shortest 12-20 path is: (12, 9, 3, 20)

The distance from 2 to 9 is 2
A shortest 2-9 path is: (2, 15, 9)

The distance from 11 to 2 is 2
A shortest 11-2 path is: (11, 6, 2)

The distance from 19 to 16 is 2
A shortest 19-16 path is: (19, 15, 16)

The distance from 6 to 9 is 2
A shortest 6-9 path is: (6, 1, 9)

The distance from 14 to 8 is 2
A shortest 14-8 path is: (14, 17, 8)

The distance from 14 to 2 is 2
A shortest 14-2 path is: (14, 5, 2)

The distance from 19 to 4 is 3
A shortest 19-4 path is: (19, 9, 1, 4)

The distance from 11 to 14 is 1
A shortest 11-14 path is: (11, 14)

The distance from 7 to 8 is 2
A shortest 7-8 path is: (7, 9, 8)

The distance from 14 to 15 is 2
A shortest 14-15 path is: (14, 1, 15)

The distance from 19 to 11 is 1
A shortest 19-11 path is: (19, 11)

The distance from 16 to 13 is 2
A shortest 16-13 path is: (16, 8, 13)

The distance from 4 to 19 is 3
A shortest 4-19 path is: (4, 1, 9, 19)

The distance from 16 to 19 is 2
A shortest 16-19 path is: (16, 15, 19)

The distance from 13 to 2 is 3
A shortest 13-2 path is: (13, 8, 17, 2)

The distance from 11 to 9 is 2
A shortest 11-9 path is: (11, 3, 9)

The distance from 16 to 13 is 2
A shortest 16-13 path is: (16, 8, 13)

The distance from 17 to 12 is 2
A shortest 17-12 path is: (17, 9, 12)

The distance from 9 to 6 is 2
A shortest 9-6 path is: (9, 1, 6)

The distance from 12 to 11 is 3
A shortest 12-11 path is: (12, 9, 3, 11)

The distance from 5 to 13 is 2
A shortest 5-13 path is: (5, 18, 13)

The distance from 18 to 11 is 2
A shortest 18-11 path is: (18, 14, 11)

The distance from 13 to 7 is 3
A shortest 13-7 path is: (13, 8, 9, 7)

The distance from 18 to 7 is 2
A shortest 18-7 path is: (18, 5, 7)

The distance from 19 to 8 is 2
A shortest 19-8 path is: (19, 9, 8)

The distance from 18 to 20 is 1
A shortest 18-20 path is: (18, 20)

The distance from 4 to 8 is 3
A shortest 4-8 path is: (4, 1, 9, 8)

The distance from 3 to 13 is 3
A shortest 3-13 path is: (3, 4, 18, 13)

The distance from 19 to 6 is 2
A shortest 19-6 path is: (19, 11, 6)

The distance from 11 to 16 is 3
A shortest 11-16 path is: (11, 6, 15, 16)

The distance from 18 to 3 is 2
A shortest 18-3 path is: (18, 4, 3)

The distance from 6 to 10 is 2
A shortest 6-10 path is: (6, 2, 10)

The distance from 3 to 5 is 1
A shortest 3-5 path is: (3, 5)

The distance from 1 to 12 is 2
A shortest 1-12 path is: (1, 9, 12)

The distance from 12 to 17 is 2
A shortest 12-17 path is: (12, 9, 17)

The distance from 9 to 10 is 2
A shortest 9-10 path is: (9, 12, 10)

The distance from 6 to 3 is 1
A shortest 6-3 path is: (6, 3)

The distance from 15 to 14 is 2
A shortest 15-14 path is: (15, 1, 14)

The distance from 13 to 5 is 2
A shortest 13-5 path is: (13, 18, 5)

The distance from 10 to 9 is 2
A shortest 10-9 path is: (10, 12, 9)

The distance from 7 to 11 is 2
A shortest 7-11 path is: (7, 6, 11)

The distance from 4 to 8 is 3
A shortest 4-8 path is: (4, 1, 9, 8)

The distance from 7 to 19 is 2
A shortest 7-19 path is: (7, 9, 19)

The distance from 16 to 16 is 0
A shortest 16-16 path is: (16)

The distance from 15 to 3 is 2
A shortest 15-3 path is: (15, 6, 3)

The distance from 19 to 9 is 1
A shortest 19-9 path is: (19, 9)

The distance from 7 to 20 is 3
A shortest 7-20 path is: (7, 5, 3, 20)

The distance from 19 to 10 is 2
A shortest 19-10 path is: (19, 17, 10)

The distance from 1 to 9 is 1
A shortest 1-9 path is: (1, 9)

The distance from 5 to 3 is 1
A shortest 5-3 path is: (5, 3)

The distance from 9 to 15 is 1
A shortest 9-15 path is: (9, 15)

The distance from 5 to 18 is 1
A shortest 5-18 path is: (5, 18)

The distance from 16 to 17 is 2
A shortest 16-17 path is: (16, 8, 17)

The distance from 1 to 13 is 3
A shortest 1-13 path is: (1, 4, 18, 13)

The distance from 12 to 9 is 1
A shortest 12-9 path is: (12, 9)

The distance from 6 to 10 is 2
A shortest 6-10 path is: (6, 2, 10)