mu 1 2 3
mu 3 2 4
mu 3 4 5
mu 5 5 6
mu 3 6 7
mu 7 7 8
mu 8 8 1
mu 8 1 2
pwr 5 4 6
iv 6 7
mu 7 2 8
mu 8 6 2
pwr 6 3 4
iv 4 5
mu 5 1 6
mu 6 4 1