mu 1 2 3 mu 3 2 4 mu 3 4 5 mu 3 5 6 mu 6 3 7 mu 7 4 8 mu 7 8 9 mu 7 9 10 mu 2 9 11 mu 2 11 12 echo "Classes 4C 6B 8A 12A 14A 15A 21B 31B" oup 8 11 12 7 10 9 8 3 4