With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Willie Nelson joined the Navy.
text_B: Karl-Heinz Tritschler -LRB- born September 16 , 1949 -RRB- , is a former football referee from Germany .. Germany. Germany. He is known for having officiated at the 1988 Summer Olympics , and the 1989 European Cup Final between AC Milan and Steaua Bucuresti .. 1988 Summer Olympics. 1988 Summer Olympics. 1989 European Cup Final. 1989 European Cup Final. AC Milan. AC Milan. Steaua Bucuresti. FC Steaua Bucuresti
not_related.