mu 1 2 3 mu 3 2 4 mu 3 4 5 mu 3 5 6 mu 6 3 7 mu 6 4 8 mu 3 7 9 mu 9 7 10 mu 10 4 11 mu 1 11 12 mu 6 11 13 mu 5 12 14 mu 11 14 15 mu 5 14 16 mu 5 16 17 mu 10 16 18 oup 14 15 14 13 7 9 12 10 11 18 17 16 3 8 6 echo "Classes 4D 6E 6F 8A 8B 9A 10C 12A 12B 12C 15C 17A 21A 30A"