Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_1840 ( "No. in series" real, "No. in season" real, "Title" text, "Directed by" text, "Written by" text, "Original air date" text, "Production code" text, "U.S. viewers (million)" text )

### Question ###
How many different people directed the episode titled 'Born under a bad sign'?

### Accurate SQL ###

SELECT COUNT("Directed by") FROM table_1840 WHERE "Title" = 'Born Under a Bad Sign'