With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Led Zeppelin released their first album in 1669.
text_B: The Denver Pop Festival was a three-day music festival promoted by Barry Fey -LRB- Feyline -RRB- on June 27 -- 29 , 1969 which was largely overshadowed by Woodstock two months later .. Denver. Denver. Barry Fey. Barry Fey. Woodstock. Woodstock Festival. The peak attendance was estimated at 50,000 .
not_related.