Li Changjiang, Duan Huanghe, Zhang Zhujiang, and He Haihe participated in a mathematics competition at the same time  After the competition, they predicted each other's ranking together  Li Changjiang said: Zhang Zhujiang is the first and I am third  Duan Huanghe said: I am first and He Haihe is fourth  Zhang Zhujiang said: He Haihe is second and I am third  He Haihe did not comment
After the results were announced, they found that the predictions were only half right
Duan Huanghe was first, He Haihe Second, Li Changjiang third, and Zhang Zhujiang fourth.