Lena was refining a small helper for the ReviewThat Labs dashboard that updates internal project IDs stored as a sequence of single numbers. She needed to ensure that when a user triggers a new version, the ID increases by exactly one across the whole sequence. For instance, an ID listed as one-two-nine should automatically transition to one-three-zero. Mark pointed out that the code also needed to handle sequences that grow in length, like when a nine turns into a one-zero, so he asked Lena to finalize that logic for the team's shared library.