With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Lisbon is the oldest city in Portugal.
text_B: Walter Barfuss -LRB- 4 February 1955 -- 24 July 1999 -RRB- was a West German bobsledder who competed in the late 1970s .. West German. West Germany. He won two bronze medals at the FIBT World Championships -LRB- Two-man  : 1978 , Four-man  : 1977 -RRB- .. World Championships. FIBT World Championships. FIBT World Championships. FIBT World Championships. FIBT World Championships 1978. FIBT World Championships 1977. Barfuss also finished seventh in the four-man event at the 1980 Winter Olympics in Lake Placid , New York .. 1980 Winter Olympics. 1980 Winter Olympics
not_related.