[GAP Forum] simple groups

[Alex Trofimuk]

-- Dear Gap Forum,
Alex Trofimuk asked:
Using function PerfectGroup(), I defined simple groups Janko J1, J2. But 
I can not find rank of their Sylow 2-subgroups. I used function 
RankPGroup().  Probably, my computer has weak power.  Help me, please, 
to find it. How to define groups Janko J3, J4 and sporadic simple groups 
Mc, Ly in system Gap. Is it possible to calculate rank of their Sylow 
2-subgroups?