[YOUKU_요우쿠] - for Chinese
▼ Direct(연출)
https://v.youku.com/v_show/id_XNDExMzM3MjQ5Ng==.html?spm=a2h3j.8428770.3416059.1

▼ Explanation (해법)

https://v.youku.com/v_show/id_XNDExMzQ3MTMyMA==.html?spm=a2h3j.8428770.3416059.1