Generate a correct and concise answer for the question based on the words in the context.

[EX Q]: Context : Once a Cop (Chinese: 超級計劃) is a 1993 Hong Kong action film directed by Stanley Tong and starring Michelle Yeoh. 
Question : Who is the director of the film, Once a Cop?
[EX A]: Stanley Tong

[EX Q]: Context : The Kano riot of 1953 refers to the riot, which broke out in the ancient city of Kano, located in Northern Nigeria, on 1 May 1953. 
Question : The point in time of Kano riot of 1953 was what?
[EX A]: 1 May 1953

[EX Q]: Context : The Midland Railway 156 Class was a class of 2-4-0 tender engines built at Derby Works between 1866--1874. 
Question : What was the year Midland Railway 156 Class entered service?
[EX A]:
1866