With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Philadelphia is home to the first U.S. hospital, founded in 1751.
text_B: Frederick William -LRB- Friedrich Wilhelm 19 July 1692 -- 21 January 1711 -RRB- was Duke of Courland and Semigallia from 1698 to 1711 .. Duke of Courland and Semigallia. Duchy of Courland and Semigallia. Frederick Wilhelm was the son of Frederick Casimir Kettler and Elisabeth Sophie of Brandenburg .. Frederick Casimir Kettler. Frederick Casimir Kettler. Kettler. Ketteler. Elisabeth Sophie of Brandenburg. Elisabeth Sophie of Brandenburg. During his reign the duchy was occupied by Swedish and later by Russian troops .. Swedish. Sweden
not_related.