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].
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Question: Trump took to Twitter on Tuesday to claim that Tennessee Republican helped "give us" the nuclear deal with Iran negotiated by President Barack Obama's administration. Earlier this month  he claimed that  Corker  is "largely responsible for the horrendous Iran Deal!"
 Corker  the chairman of the Senate Foreign Relations Committee   was in fact a vehement critic of the deal that emerged from international negotiations in the summer of 2015. After the deal was unveiled   he  wrote in an op-ed for The Washington Post that "Congress should reject this deal and send it back to the President."
 Corker  plotted efforts to block the deal  banding with Republicans -- and even some Democrats -- in an attempt to block the deal.
The following month   Corker  did just that  joining with the bipartisan group to vote against the deal. A procedural vote to move forward a resolution to reject the nuclear deal fell shy of the required 60-vote threshold.
Even before that vote   Corker  helped push through the legislation that would ultimately grant Congress powers to review the deal  which the Obama administration contemplated approving without congressional oversight.
 Corker  said such an attempt would be "a direct affront to the American people and seeks to undermine Congress' appropriate role" in a March 2015 letter to Obama.
 Corker 's calls for congressional review of the nuclear deal that was still being negotiated in the spring of 2015 ultimately led to the Iran Nuclear Agreement Review Act  which Obama ultimately signed despite initially opposing the measure.
That could be what White House press secretary Sarah Sanders was referring to on October 10 when she claimed: " Sen. Corker  worked with Nancy Pelosi and the Obama administration to pave the way for that legislation and basically rolled out the red carpet for the Iran deal  and those are pretty factual."
 Corker  defended the bill against that criticism in September 2015  noting that the legislation "actually took power back from the president."
"Without it  he could have unilaterally implemented the deal immediately. The President never would have been forced to submit the agreement to Congress and there would have been no review and no debate on this critical national security issue "  Corker  said then.
Trump's criticism of  Corker  on the Iran deal is also curious given that Trump initially considered  Corker  as a candidate for vice president and later secretary of state  in large part due to his foreign policy chops.

Answer: Corker


Question: He âs back!
Legendary talk show host  David Letterman âs new Netflix show  âMy Next Guest Needs No Introduction â debuts Jan. 12  and former President Barack Obama is slated to be the first guest.
âI had a show for a long time and then I didnât have a show for a long time  and I canât tell you how great it is to be out of the damn house â  Letterman  jokes in the trailer.
The trailer doesnât indicate what  Letterman  and Obama will talk about  but itâs possible the current administration will be a hot topic on the series considering  Letterman  has spoken out against President Donald Trump.

Answer: David Letterman


Question: WASHINGTON/SEOUL (Reuters) - U.S. Vice President Mike Pence was scheduled to meet with North Korean officials  including leader Kim Jong Unâs sister  while in South Korea for the Winter Olympics this month but the North Koreans canceled at the last minute  U.S. officials said on Tuesday.
Pence was going to meet with North Korean leader Kim Jong Unâs younger sister  Kim Yo Jong  and the nominal head of state  Kim Yong Nam  but the North Koreans called off the Feb. 10 meeting two hours before it was set to start  a U.S. official said  confirming a story first reported by the Washington Post.
U.S. Vice President Mike Pence  North Korea's nominal head of state Kim Yong Nam  and  North Korean leader Kim Jong Un's younger sister Kim Yo Jong  attend the Winter Olympics opening ceremony in Pyeongchang  South Korea February 9  2018. Yonhap via REUTERS
âThis administration will stand in the way of  Kim âs desire to whitewash their murderous regime with nice photo ops at the Olympics. Perhaps thatâs why they walked away from a meeting or perhaps they were never sincere about sitting down â Ayers said in the statement.
 Kim Jong Un   through  his sister   invited South Korean President Moon Jae-in to Pyongyang to begin talks âsoon.â

Answer:
Kim Jong Un