Passage: Conversion from Julian or Gregorian calendar years to the Human Era can be achieved by adding 10,000 to the AD/CE year. The present year, 2019, can be transformed into a Holocene year by adding the digit "1" before it, making it 12,019 HE.  Years BC/BCE are converted by subtracting the BC/BCE year number from 10,001.

Question: How much needs to be added to AD to convert Julian calendar?
10,000