30 50
B D A BC DB DD DA DC AB AD AA AC CB CD CA BCC DBB DBD DBA DBC DDB DDD DDA DDC DAB DAD DAA DAC DCB DCD DCA DCC ABB ABD ABA ABC ADB ADD ADA ADC AAB AAD AAA AAC ACB ACD ACA ACC CBB CBD 
D A C DB DD DA DC AB AD AA AC CB CD CA CC DBB DBD DBA DBC DDB DDD DDA DDC DAB DAD DAA DAC DCB DCD DCA DCC ABB ABD ABA ABC ADB ADD ADA ADC AAB AAD AAA AAC ACB ACD ACA ACC CBB CBD CBA