With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Charles Dickens was born in February 1812.
text_B: William Burns Smith -LRB- November 11 , 1844 - November 23 , 1917 -RRB- was the Mayor of Philadelphia from 1884 to 1887 .. Mayor of Philadelphia. Mayor of Philadelphia
not_related.