Not all GR have this same seating arrangement... I was telling about this specific GR!!
Seating arrangement for 22405/06 BGP GR:-
1 :: LB
2 :: MB
3 :: UB
4...
more... :: LB
5 :: MB
6 :: UB
7 :: SL
8 :: SU
9 :: LB
10 :: MB
11 :: UB
12 :: LB
13 :: MB
14 :: UB
15 :: SL
16 :: SU
17 :: LB
And so on...
(normal 3A arrangement)