With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Heartlight is the second track on Diamond's album.
text_B: Choi Woo Hyuk -LRB- 최우혁 , born October 28 , 1985 -RRB- is a South Korean actor under Bel Actors Entertainment and was popularly known as the young `` Yoon Junseo '' in ` hit ' Korean drama Endless Love 1  : Autumn in My Heart .. Choi. Choi ( Korean name ). Bel Actors Entertainment. Bel Actors Entertainment. Autumn in My Heart. Autumn in My Heart. He debuted as an actor on 1993 .
not_related.