2. 1231456
3. 1231233452
4. 12324545
5. 12 324
6. 123 45623
7. 123423
8. 123425
9. 123 4565
10. 1234567896
The coding above represents patterns of ten famous cities' names, where similar letters are represented by a certain digit, like Baku would be 1234 and Oslo 1231.
To minimize ambiguity, the order of the names is alphabetical.
Try to restore the official list.