Input: Read this: The onset of symptoms in myocardial infarction (MI) is usually gradual, over several minutes, and rarely instantaneous. Chest pain is the most common symptom of acute MI and is often described as a sensation of tightness, pressure, or squeezing. Chest pain due to ischemia (a lack of blood and hence oxygen supply) of the heart muscle is termed angina pectoris. Pain radiates most often to the left arm, but may also radiate to the lower jaw, neck, right arm, back, and upper abdomen, where it may mimic heartburn. Levine's sign, in which a person localizes the chest pain by clenching their fists over their sternum, has classically been thought to be predictive of cardiac chest pain, although a prospective observational study showed it had a poor positive predictive value.
Question: What is a good way to predict a heart attack?

Output: unanswerable

Input: Read this: The city proper is home to less than one-thirteenth of the population of South Florida. Miami is the 42nd-most populous city in the United States. The Miami metropolitan area, which includes Miami-Dade, Broward and Palm Beach counties, had a combined population of more than 5.5 million people, ranked seventh largest in the United States, and is the largest metropolitan area in the Southeastern United States. As of 2008[update], the United Nations estimates that the Miami Urban Agglomeration is the 44th-largest in the world.
Question: Where does Miami-Dade rank in population among metropolitan areas in the US?

Output: seventh

Input: Read this: There are dozens of other chemical neurotransmitters that are used in more limited areas of the brain, often areas dedicated to a particular function. Serotonin, for examplethe primary target of antidepressant drugs and many dietary aidscomes exclusively from a small brainstem area called the Raphe nuclei. Norepinephrine, which is involved in arousal, comes exclusively from a nearby small area called the locus coeruleus. Other neurotransmitters such as acetylcholine and dopamine have multiple sources in the brain, but are not as ubiquitously distributed as glutamate and GABA.
Question: Serotonin comes from what part of the brain?

Output: Raphe nuclei

Input: Read this: After the early 20th century revolutions, shifting alliances of China's regional warlords waged war for control of the Beijing government. Despite the fact that various warlords gained control of the government in Beijing during the warlord era, this did not constitute a new era of control or governance, because other warlords did not acknowledge the transitory governments in this period and were a law unto themselves. These military-dominated governments were collectively known as the Beiyang government. The warlord era ended around 1927.
Question: When did the warlord era end?

Output:
around 1927