remove duplicate lines with condition

hi to all

Does anyone know if there's a way to remove duplicate lines which we consider the same only if they have the first and the second column the same?
For example I have :

us2333 bbb 5
us2333 bbb 3
us2333 bbb 2

and I want to get

us2333 bbb 10

The thing is I cannot remove the 3rd line and then use uniq -c
as the 3rd line holds an information which is needed.Besides,it is the sum
of the 3rd column (the 3rd column is a result of a previous uniq -c)

awk '{ A[$1 " " $2] += $3 } END { for(X in A) print X, A[X] }' filename

awesome!