With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Swedish Empire was ruled by Gustav II Adolf for 21 years.
text_B: The Columbia University protests of 1968 were among the many student demonstrations that occurred around the world in that year .. Columbia University. Columbia University. The Columbia protests erupted over the spring of that year after students discovered links between the university and the institutional apparatus supporting the United States ' involvement in the Vietnam War , as well as their concern over an allegedly segregatory gymnasium to be constructed in the nearby Morningside Park .. Vietnam War. Vietnam War. Morningside Park. Morningside Park ( New York City ). The protests resulted in the student occupation of many university buildings and the eventual violent removal of protesters by the New York City Police Department .. New York. New York City. New York City Police Department. New York City Police Department
not_related.