Definition: Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.

Positive Example 1 -
Input: Context : Isaac Nicola Romero (1916 in Havana, Cuba -- 1997) was a prominent Cuban guitarist and one of the founders of the modern Cuban Guitar School. 
Answer : Havana
Output: What was Isaac Nicola's city of birth?

Positive Example 2 -
Input: Context : Tweetie Pie won the Academy Award for Best Animated Short Film, breaking Tom and Jerry's streak of four consecutive wins on the category. 
Answer : Academy Award for Best Animated Short Film
Output: What award was Tweetie Pie nominated for?

Negative Example 1 -
Input: Context : An Officer and a Gentleman is a 1982 American drama/romance film that stars Richard Gere, Debra Winger and Louis Gossett, Jr., who won the Academy Award for Best Supporting Actor for the film, and was produced by Lorimar Productions for Paramount Pictures. 
Answer : Academy Award for Best Supporting Actor
Output: What time does An Officer and a Gentleman belongs to?

Negative Example 2 -
Input: Context : Isaac Nicola Romero (1916 in Havana, Cuba -- 1997) was a prominent Cuban guitarist and one of the founders of the modern Cuban Guitar School. 
Answer : Cuban Guitar School
Output: What was Isaac Nicola's city of birth?

Now complete the following example -
Input: Context : In cryptography, DES-X (or DESX) is a variant on the DES (Data Encryption Standard) symmetric-key block cipher intended to increase the complexity of a brute force attack using a technique called key whitening. 
Answer : Data Encryption Standard
Output: 


Output: Which is the basis of DES-X?