你可以嘗試用樹狀圖喔！
| 想法1 | 想法2 | ||||||||
| ABC ABD ABE ABF ACB ACD ACE ACF ADB ADC ADE ADF |
BAC BAD BAE BAF BCA BCD BCE BCF BDA BDC BDE BDF |
CAB CAD CAE CAF CBA CBD CBE CBF CDA CDB CDE CDF |
DAB DAC DAE DAF DBA DBC DBE DBF DCA DCB DCE DCF |
EAB EAC EAD EAF EBA EBC EBD EBF ECA ECB ECD ECF |
FAB FAC FAD FAE FBA FBC FBD FBE FCA FCB FCD FCE |
ABC ABD ABE ABF ACD ACE ACF ADE ADF |
BCD BCE BCF BDE BDF |
CDE CDF |
DEF |