Testcase confusion

In test.py @ github there's such case:

"input": [['Dorothea', 'Vincent', 'Irene', 'Lula', 'Paulette', 'Bill', 'Virginia'], []],
"answer": [5, ...]

And from my code I can find 6 chains:

1. ['Dorothea', 'Vincent', 'Irene', 'Lula', 'Paulette', 'Bill', 'Virginia']
2. ['Dorothea', 'Virginia', 'Bill', 'Paulette', 'Lula', 'Irene', 'Vincent']
3. ['Dorothea', 'Irene', 'Paulette', 'Vincent', 'Virginia', 'Lula', 'Bill']
4. ['Dorothea', 'Bill', 'Lula', 'Virginia', 'Vincent', 'Paulette', 'Irene']
5. ['Dorothea', 'Lula', 'Vincent', 'Bill', 'Irene', 'Virginia', 'Paulette']
6. ['Dorothea', 'Paulette', 'Virginia', 'Irene', 'Bill', 'Vincent', 'Lula']

Am I wrong?