Final answer:
Upon returning to the office after mail delivery, standard procedures include checking in with supervision, filing delivery records, returning undelivered mail, and possibly clocking out.
Step-by-step explanation:
The input used when arriving back at the office after delivering all of the mail on the streets could vary, but typically it would involve the process of checking in with a supervisor, filing any delivery records, returning undelivered mail, and perhaps clocking out if it is the end of the work shift. These are standard post-delivery procedures for postal workers or couriers to ensure that all mail has been distributed correctly and any issues are reported. Additionally, there may be protocols for vehicle maintenance if a company vehicle was used for the deliveries.