mu 1 2 3 mu 3 2 4 mu 3 4 5 mu 3 5 6 mu 4 6 7 mu 6 7 8 mu 8 7 9 mu 3 6 10 mu 6 5 11 mu 10 11 12 mu 1 11 13 mu 12 13 14 mu 5 12 15 mu 15 9 16 oup 7 12 14 16 9 3 6 7 echo "Classes 6A 9A 9B 14A 19C 26C 37D"