Not if people schedule back to back meetings. The point of starting it on the 5 and ending on 0 is that you cant schedule a meeting with no gap after the previous. You will always have at least 5 minutes.
Alternatively, tell the people in meeting B that you will be 5 minutes late. Lateness communicated in advance is far less disruptive than unannounced lateness.
If neither of those are possible, reschedule one or the other meeting.
If it's impossible to reschedule either meeting, and this happens a lot, then there's a larger problem.