Try find the value of L first instead of G, that may help.
L cannot equal two, which means it has to equal 1 (Nothing else can be added to become 2 in this problem). Which also tells us that we have to carry a number over, meaning O greater than or equal to 3 (Considering both 1 and 2 are used). We'll worry about that in a second, though.
So this is what we have:
GO
+ S1O8
S2OP
Understand so far both of ye? (Just assuming Funnel gets it thus far :u)