ID,Sire,Dam
a1,0,0
a2,0,0
a3,0,0
a4,a1,a2
a5,a1,a2
a6,a1,a3
a7,a1,a3
a8,a4,a6
a9,a4,a6
a10,a5,a7
a11,a9,a10
a12,a9,a10
