input:

10000
2 1
1 2
29 28
13 19
16 5
21 7
22 10
10 2
1 18
27 13
10 3
11 23
12 22
11 7
7 17
29 17
9 1
28 21
2 18
13 9
4 25
20 16
5 14
20 7
14 4
12 8
8 24
17 19
15 1
11 6
26 9
13 12
13 9
12 2
6 12
9 11
5 2
8 10
6 10
3 10
7 1
7 5
8 9
4 1
12 11
10 6
2 8
12 4
5 10
11 1
3 1
10 1
12 9
9 1
8 3
7 1
35 35
13 8
34 1...

output:

2 
7 10 11 14 15 16 17 18 20 22 24 25 26 27 28 
3 4 5 8 9 10 12 
5 6 7 11 
7 8 9 13 18 20 23 25 29 30 31 32 33 34 35 
4 6 7 11 16 18 
2 
1 5 
1 3 4 13 14 15 18 22 26 27 28 31 33 37 42 43 45 47 48 50 
8 13 16 18 19 21 22 23 26 27 31 34 36 
6 10 11 12 
2 6 12 16 17 19 
5 6 7 9 15 17 18 20 21 23 25 26 ...

result:

wrong answer vertex 20 is not covered (test case 2)