醫學四
A D A D B    C B A C C
C A B B C    D B B C C
A B D B A    C D A B D
A C D B B    C B D A D
B A D B C    C A A B A
A B A C B    D C D B C
A A B A B    B D D D B
B B B A C    A A C C B