id	sire	dam
off1	sire1	dam1
off2	sire2	dam2
off3	sire3	dam3
off4	sire4	dam4
off5	sire5	dam5
sire1	off1	grandmother1
sire2	grandfather2	grandfather2
sire3	grandfather3	grandfather3
sire4	grandfather4	grandmother4
sire5	grandfather5	grandmother5
dam1	grandfather6	grandmother6
dam2	grandfather7	grandmother7
dam3	grandfather8	grandmother8
dam4	0	0
dam5	0	0