Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What year was the role nan taylor, alias of nan ellis, aka mrs. andrews and directed by William keighley?

### Inputs:
table_name: table, columns: ['Year', 'Film', 'Role', 'Leading Man', 'Director']

### Response:
SELECT SUM Year FROM table WHERE Role = nan taylor, alias of nan ellis, aka mrs. andrews AND Director = william keighley