With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Doctor Who is British.
text_B: John W. Stephens -LRB- October 13 , 1834 -- May 21 , 1870 -RRB- was a state senator from North Carolina .. state senator. state senator. North Carolina. North Carolina. He was assassinated by the Ku Klux Klan on May 21 , 1870 .. Ku Klux Klan. Ku Klux Klan
not_related.