With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Justin Timberlake's birthday takes place on January 31.
text_B: Algebraic Geometry is an influential algebraic geometry textbook written by Robin Hartshorne and published by Springer-Verlag in 1977 .. Robin Hartshorne. Robin Hartshorne. algebraic geometry. algebraic geometry. textbook. textbook. Springer-Verlag. Springer-Verlag
not_related.