With no explanation, label text_A→text_B with either "NOT ENOUGH INFO", "REFUTES" or "SUPPORTS".
text_A: Conan O'Brien is a dog .
text_B: With the retirement of David Letterman on May 20 , 2015 , O'Brien became the longest-working of all current late-night talk show hosts in the United States , at 22 years .
REFUTES.