With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The 2011 FIFA U-20 World Cup had matches in eight cities.
text_B: Rugby sevens , for the 2013 Bolivarian Games , took place from 17 November to 19 November 2013 .. Rugby sevens. Rugby sevens. 2013 Bolivarian Games. 2013 Bolivarian Games
not_related.