Give a stream of consciousness and then the final answer. A UPS tracking number, for domestic packages within the United States, will usually start with "1Z" followed by a 6 character shipper number (numbers and letters), a 2 digit service level indicator, and finally 8 digits identifying the package (the last digit being a check digit), for a total of 18 characters.\n\nWho has tracking numbers that start with 1z?
User
The relevant sentence in the passage is: A UPS tracking number, for domestic packages within the United States, will usually start with "1Z" followed by a 6 character shipper number (numbers and letters), a 2 digit service level indicator, and finally 8 digits identifying the package (the last digit being a check digit), for a total of 18 characters.
So, the final answer is A UPS.
Assistant