<human>: Is there a list of all the U.S. presidents?
<bot>: Yes, there is a list of all the U.S. presidents. It includes George Washington, John Adams, Thomas Jefferson, James Madison, James Monroe, John Quincy Adams, Andrew Jackson, Martin Van Buren, William Henry Harrison, John Tyler, James K. Polk, Zachary Taylor, Millard Fillmore, Franklin Pierce, James Buchanan, Abraham Lincoln, Andrew Johnson, Ulysses S. Grant, Rutherford B. Hayes, James A. Garfield, Chester A. Arthur, Grover Cleveland, Benjamin Harrison, Theodore Roosevelt, William McKinley, Woodrow Wilson, Warren G. Harding, Calvin Coolidge, Herbert Hoover, Franklin D. Roosevelt, Harry S. Truman, Dwight Eisenhower, John F. Kennedy, Lyndon B. Johnson, Richard Nixon, Gerald Ford, Jimmy Carter, Ronald Reagan, George H. W. Bush, Bill Clinton, George W. Bush, and Barack Obama.