Instructions: This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
Input: Passage: The Fujiwara controlled the throne until the reign of Emperor Go-Sanjo (1068-1073), the first emperor not born of a Fujiwara mother since the ninth century. Go-Sanjo, determined to restore imperial control through strong personal rule, implemented reforms to curb Fujiwara influence. He also established an office to compile and validate estate records with the aim of reasserting central control. Many shoen were not properly certified, and large landholders, like the Fujiwara, felt threatened with the loss of their lands. Go-Sanjo also established the In-no-cho (ja: Office of the Cloistered Emperor), which was held by a succession of emperors who abdicated to devote themselves to behind-the-scenes governance, or insei.
Output:
Who was the last emperor born to a Fujiwara mother?