Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Example Input: Context: With transform plate boundaries, the two slabs of lithosphere are sliding past each other in opposite directions. The boundary between the two plates is a transform fault. Transform faults on continents separate two massive plates of lithosphere. As they slide past each other, they may have massive earthquakes. The San Andreas Fault in California is perhaps the worlds most famous transform fault. Land on the west side is moving northward relative to land on the east side. This means that Los Angeles is moving northward relative to Palm Springs. The San Andreas Fault is famous because it is the site of many earthquakes, large and small. (Figure At the San Andreas Fault in California, the Pacific Plate is sliding northeast relative to the North American plate, which is moving southwest. At the northern end of the picture, the transform boundary turns into a subduction zone. Transform plate boundaries are also found in the oceans. They divide mid-ocean ridges into segments. In the diagram of western North America, the mid-ocean ridge up at the top, labeled the Juan de Fuca Ridge, is broken apart by a transform fault in the oceans. A careful look will show that different plates are found on each side of the ridge: the Juan de Fuca plate on the east side and the Pacific Plate on the west side. 
 Question: over millions of years, which direction would you find los angeles in relation to where it is now?
Example Output: north

Example Input: Context: Hoping to rebound from a divisional home loss to the Eagles, the Cowboys flew to Bank of America Stadium for a Week 16 Saturday night duel with the Carolina Panthers. In the first quarter, Dallas shot first with QB Tony Romo completing a 10-yard TD pass to WR Terrell Owens for the only score of the period. In the second quarter, the 'Boys continued their assault as RB Marion Barber got a 5-yard TD run. The Panthers would get on the board with QB Matt Moore completing an 11-yard TD pass to WR Steve Smith. The Cowboys end the half with rookie kicker Nick Folk getting a 42-yard field goal. In the third quarter, Carolina started to try a comeback as kicker John Kasay getting a 37-yard field goal for the only score of the period. In the fourth quarter, Dallas would respond with Folk kicking a 23-yard field goal. The Panthers tried to rally as Kasay nailing a 25-yard field goal, yet the 'Boys were able to hold off every possible attempt. With the win, the Cowboys improved to 13-2 and clinched homefield through NFC Playoffs with Green Bay's loss to Chicago on Sunday. Terrell Owens (5 receptions for 48 yards and 1 touchdown) left the game in the second quarter with a high left ankle sprain. 
 Question: Which player kicked both the longest and shortest field goals?
Example Output: nick folk

Example Input: Context: Alzheimer's disease (AD) is the most common cause of dementia in humans. A pathological hallmark in the brain of an AD patient is extracellular amyloid plaques formed by accumulated beta-amyloid protein (Abeta), a metabolic product of amyloid precursor protein (APP). Studies have revealed a strong genetic linkage in the early-onset familial form (<60 years old) of AD. For example, some mutant APPs are transmitted dominantly and are segregated with inheritance of early onset AD. These mutants facilitate Abeta production. The "Swedish" mutations (APP(SW)) and the "London" mutation (APP(LON)) are examples of these mutants. Selective silencing of these mutant alleles holds therapeutic promise for AD. Here we show that the expression of the mutant APPs was selectively inhibited by RNA interference. The best selectivity was obtained when the mismatches were centrally placed in the antisense strand of small interfering RNAs. Introducing an additional mismatch in the antisense strand may improve the selectivity. The addition of a G at 5' end of the antisense strand may enhance the efficacy of gene silencing by RNA interference. Our results illustrate the guiding principles for selection of targeted sequences to achieve allele-specific silencing. The sequences that are effective to silence APP(SW) and APP(LON) as identified in this study may be useful in both in vivo and in vitro studies to investigate the pathophysiological role of APP(SW) and APP(LON) in AD development. 
 Question: Which disease the London mutation involved in?
Example Output:
alzheimer's disease