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