(LEAD) (Olympics) S. Korea's Lee Seung-hoon wins first gold in men's mass start speed skating

(ATTN: ADDS more details from 4th para, photos)

By Kim Boram and Kang Yoon-seung

GANGNEUNG, South Korea, Feb. 24 (Yonhap) -- Veteran South Korean skater Lee Seung-hoon became the inaugural Olympic champion in men's mass start speed skating, at the Py