With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Wladimir Klitschko has fought in 29 heavyweight title fights.
text_B: The first world record in the men 's 400 metres freestyle in long course -LRB- 50 metres -RRB- swimming was recognised by the International Swimming Federation -LRB- FINA -RRB- in 1908 .. freestyle. freestyle swimming. International Swimming Federation. International Swimming Federation. In the short course -LRB- 25 metres -RRB- swimming events the world 's governing body recognizes world records since 3 March 1991 .
not_related.