30 50
D D D C C B DD DD DD DD DD DD DC DC DC DB DB CC CC CC CC CC CB CB BB BB BB DDD DDD DDD DDD DDD DDD DDD DDD DDD DDD DDC DDC DDC DDC DDB DDB DDB DCC DCC DCC DCC DCB DBB 
C B A B A A CC CB CA BB BA AA BB BA AA CA AA DB DA BB BA AA DA AA DA CA AA CCC CCB CCA CBB CBA CAA BBB BBA BAA AAA BBB BBA BAA AAA CCA CAA AAA BBB BBA BAA AAA AAA CCA