This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Ex Input:
Passage: Season ten of the series premiered on January 19, 2011. Many changes were introduced this season, from the format to the personnel of the show. Jennifer Lopez and Steven Tyler joined Randy Jackson as judges following the departures of Simon Cowell (who left to launch the U.S. version of The X Factor), Kara DioGuardi (whose contract was not renewed) and Ellen DeGeneres, while Nigel Lythgoe returned as executive producer. Jimmy Iovine, chairman of the Interscope Geffen A&M label group, the new partner of American Idol, acted as the in-house mentor in place of weekly guest mentors, although in later episodes special guest mentors such as Beyoncé, will.i.am and Lady Gaga were brought in. Question: Who replace weekly mentors as a more permanent mentor on American Idols tenth season? 

Ex Output:
Jimmy Iovine


Ex Input:
Passage: Lafayette Park is a revitalized neighborhood on the city's east side, part of the Ludwig Mies van der Rohe residential district. The 78-acre (32 ha) development was originally called the Gratiot Park. Planned by Mies van der Rohe, Ludwig Hilberseimer and Alfred Caldwell it includes a landscaped, 19-acre (7.7 ha) park with no through traffic, in which these and other low-rise apartment buildings are situated. Immigrants have contributed to the city's neighborhood revitalization, especially in southwest Detroit. Southwest Detroit has experienced a thriving economy in recent years, as evidenced by new housing, increased business openings and the recently opened Mexicantown International Welcome Center. Question: What district is Lafayette Park a part of?

Ex Output:
Ludwig Mies van der Rohe residential district


Ex Input:
Passage: For centuries, various peoples in modern-day Nigeria traded overland with traders from North Africa. Cities in the area became regional centres in a broad network of trade routes that spanned western, central and northern Africa. In the 16th century, Spanish and Portuguese explorers were the first Europeans to begin significant, direct trade with peoples of modern-day Nigeria, at the port they named Lagos and in Calabar. Europeans traded goods with peoples at the coast; coastal trade with Europeans also marked the beginnings of the Atlantic slave trade. The port of Calabar on the historical Bight of Biafra (now commonly referred to as the Bight of Bonny) become one of the largest slave trading posts in West Africa in the era of the transatlantic slave trade. Other major slaving ports in Nigeria were located in Badagry, Lagos on the Bight of Benin and on Bonny Island on the Bight of Biafra. The majority of those enslaved and taken to these ports were captured in raids and wars. Usually the captives were taken back to the conquerors' territory as forced labour; after time, they were sometimes acculturated and absorbed into the conquerors' society. A number of slave routes were established throughout Nigeria linking the hinterland areas with the major coastal ports. Some of the more prolific slave traders were linked with the Oyo Empire in the southwest, the Aro Confederacy in the southeast and the Sokoto Caliphate in the north. Question: Who were the major slave traders through Nigeria from the southwest?

Ex Output:

Oyo Empire