Correct

坚苦

/ jiān kǔ / 
Strokes

Example

As an Adjective

steadfast and assiduous

1
Jiānkǔ
坚苦
de
的
zhēngzhá
挣扎

grim struggle

2
Jiānkǔ
坚苦
de
的
rènwu
任务

arduous task