Given a document, find the main entity about whom the author is writing. Write the full name if mentioned in the text. Note that URLs in the text have been replaced with [Link].

Q: Sam Querrey gave the United States a winning start in its bid to reach Saturday's final at the World Team Cup.
 Querrey beat Jan Hajek 6-3  7-5 on Thursday to put the U.S. 1-0 up against the Czech Republic in the Red Group and remain unbeaten in his three singles this week.
 "So far so good " said Querrey. "I thought today was the best I played out of the three matches. So I'm pretty excited."
 Hajek claimed the first break  when Querrey ended a long rally with a forehand error  to go 3-1 up but the American player responded by winning the next five games in a row to take the opening set.
 Both players saved a break point late in the second set before Querrey broke at 6-5  converting his third match point.
 "I've been working this week to try and hit my forehand a little bigger. I felt I did that today " said Querrey. "I felt pretty much anytime I got a forehand  I was able to take control of the point."
 Querrey said his win takes the pressure off the U.S. ahead of Friday's matches.
 "A little bit  yes. I think John (Isner) can go out there and play a little more freely  which is a good thing " Querrey said. "When we have the lead  you can swing away a little bit more than if we were 1-0 down.
 "Then  the Bryan brothers  we expect them to win every match. Hopefully  they are going to do that again."

A: Sam Querrey
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Q: Bitcoin's price has fully recovered from  its  recent slump after  JPMorgan CEO Jamie Dimon  called it a fraud and Chinese regulators cracked down on exchanges.
The cryptocurrency had a drawdown of up to 14% in the 10 days after September 12  when  Dimon  compared it to the tulip bubble of the 1600s and vowed to fire traders who used it.
By Thursday  bitcoin had all of the losses. It was up nearly 2% from the lows on the day  Dimon  spoke  at $4157.31 per coin at 10:28 a.m. ET.
The move illustrates bitcoin's wild volatility; it's gained 331% this year  unheard of for any major currency and most financial assets. It also shows why many Wall Street professionals like  Dimon  don't see it as a legitimate store of value but as a speculative instrument.

A: Jamie Dimon
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Q: In an interview with Fox News Sunday 's Chris Wallace , Mitt Romney acknowledged just how much his "47 percent" comments -- in which he all but wrote off the votes of half the country -- had negatively impacted his chances of being president : "That hurt . 
Romney 's admission of the damage done got us to thinking -LRB- again -RRB- about why exactly the remark hurt him so badly . 
Candidates need to adjust accordingly or face the prospect of adding their names to a list that Romney headlines at the moment . 
The conventional wisdom is that "47 percent" hurt so much because it played directly into the stereotype of Romney as an out-of-touch rich guy that President Obama and his campaign were playing up . 
The power of these "candid candidate" moments is that they present a jarringly different image of a politician than the one he or she is presenting to the public and raise questions among voters about who the real Mitt Romney or Tom Daschle or Bob Etheridge actually is . 
The truly terrible thing for Romney was that the remarks not only came directly out of Romney 's mouth but were also documented on video . 
Imagine for a second if Romney 's "47 percent" comments had never been captured on video and rather only been quoted by someone in attendance . 
Yes , it still would have been a story that Romney would have had to address but it 's hard to imagine that it would have been the definitive moment of the campaign -- as it turned out to be .

A:
Mitt Romney
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