Classify the relation of question with context to one of these categories: 1) award received, 2) based on, collection, 3) conflict, 4) constellation, 5) convicted of, 6) date of death, 7) director, 8) drafted by, 9) educated at, 10) medical condition, 11) military branch, 12) narrative location, 13) occupation, 14) original network, 15) parent company, 16) point in time, 17) production company, 18) residence, 19) series, 20) service entry, 21) sex or gender, 22) spouse, 23) standards body question.

Ex Input:
Context : Following ``The Hawking Excitation'', there was a three-week break before the next episode, ``The Stag Convergence'', aired. 
Question : What series is the episode The Hawking Excitation part of?

Ex Output:
series


Ex Input:
Context : Blackadder Goes Forth is the fourth and final series of the BBC sitcom Blackadder, written by Richard Curtis and Ben Elton, which aired from 28 September to 2 November 1989 on BBC One. 
Question : Where can you find the show Blackadder Goes Forth?

Ex Output:
original network


Ex Input:
Context : The Norwegian company Kongsberg Defence & Aerospace teamed up with Raytheon and initiated the NASAMS programme as a cooperative effort for the Royal Norwegian Air Force. 
Question : What year did NASAMS come into use?

Ex Output:

service entry