(LEAD) (Olympics) S. Korea's Cha Min-kyu wins surprise silver in men's 500m speed skating

(ATTN: ADDS more details from 5th para, photo)

By Kim Boram and Kang Yoon-seung

GANGNEUNG, South Korea, Feb. 19 (Yonhap) -- South Korea's Cha Min-kyu on Monday made a surprise run at the PyeongChang Winter Olympics to capture silver in the men's 500