72201
Although many dates were struck in small numbers , the rarest was produced at the San Francisco Mint in 1870 ( 1870-S ) ; only one is known with certainty to exist .
 San Francisco Mint
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 San Francisco Mint