mu 1 2 3
mu 3 2 4
mu 4 2 5
mu 5 2 6
mu 6 2 7
mu 7 2 8
mu 8 8 9
mu 9 3 10
mu 7 4 9
mu 9 5 11
iv 11 9
mu 9 10 12
mu 12 11 2
