The format1:
<Event number> <Number of entries in this event> # lines after this line are particle entries
<Status> <PDG ID> <1st Mother> <2nd Mother> <1st Daughter> <2nd Daughter> <Px> <Py> <Px> <E> <Mass> <x> <y> <z> <t>
where Px/Py/Pz are in GeV/c, E is in GeV, and M is in GeV/c$^2$. x/y/z are in mm and t is in mm/c ($\approx 3.33\times 10^{-12}$s)
Example:
1 1
1 -13 0 0 0 0 0.203136 -1.59432 -0.0112567 1.61072 0.105658 35.4066 141.55 0.889118 0.0
2 1
1 -13 0 0 0 0 0.298221 -1.14618 -0.355804 1.24114 0.105658 -15.9746 141.55 90.8073 0.0
3 1
1 -13 0 0 0 0 -2.14479 -9.28636 7.55425 12.162 0.105658 105.682 141.55 89.0959 0.0
4 1
1 -13 0 0 0 0 -0.0220145 -0.0559374 -0.0194655 0.12311 0.105658 82.5655 141.55 55.4602 0.0
5 1
1 -13 0 0 0 0 0.00821803 -0.203629 -0.0429171 0.233534 0.105658 145.534 141.55 118.808 0.0