兩兩組合:總***有36個
組成6個數字:a_
:123123,
123132,123213,123231,123312,123321
b_:132123,132132,132213,132,231,132312,132321
c
_:213123,213132,213213,213231,213312,213321
d_:231123,231132,231213,231231,231312,231321
e_:312123,312132,312213,312231,312312,312321
f_:321123,321132,321213,321231,321312,321321