mu 1 2 3
mu 3 2 4
mu 3 4 5
mu 3 5 6
mu 6 3 7
mu 5 2 8
mu 5 8 2
mu 7 7 6
iv 6 7
mu 4 4 8
mu 4 8 9
mu 8 9 1
mu 1 7 8
mu 6 8 1
