mu 1 2 3 
mu 3 2 4 
mu 3 4 5 
mu 5 4 6
mu 3 6 7
pwr 3 7 8
mu 3 7 9
mu 9 4 10
mu 10 5 11
mu 5 7 12
mu 12 4 13
mu 13 5 14
mu 5 6 15
mu 3 15 16
mu 3 16 17
mu 3 17 18
mu 17 4 19
pwr 5 19 20

echo "Classes 14ABCDEF 63ABCDEF 73ABCDEF 14GHI 18ABC 21GH 6C 18D 24A-B"
oup 9   11 20 8 5 10 14 18 2 3