mu 1 2 3 mu 3 2 4 mu 3 4 5 mu 3 5 6 mu 2 4 7 mu 2 6 8 mu 5 7 9 mu 4 9 10 mu 6 9 11 mu 1 9 12 mu 12 2 13 mu 1 11 14 mu 14 10 15 echo "Classes 4B 6CD 6E 9AB 12AB 4D 6G 6H 6I 8A 10A 12C" oup 12 11 13 10 2 5 8 15 7 9 4 3 6