input:

4
2
1 2
2 1
3
1 2 3
2 1 3
3 2 1
4
1 2 3 4
2 1 3 4
3 2 4 1
4 2 1 3
5
1 2 4 3 5
2 4 1 3 5
3 5 1 2 4
4 2 1 3 5
5 3 1 2 4

output:

1 2
1 2
2 3
1 2
2 3
2 4
1 2
1 4
2 3
4 5

result:

wrong answer ord[1] didn't pass the test (test case 4)