I am not sure of the proper place to post this, so please advise me if it should be put elsewhere...

I have a very large amount of data. ~29,000 lines. It is in this format currently:
A B C D E F G H I
18 256 0 0 0 0 0 0 0
18 0 512 0 0 0 0 0 0
18 0 0 256 0 0 0 0 0
19 71000 0 0 0 0 0 0 0
19 0 9000 0 0 0 0 0 0
19 0 0 0 0 0 0 140 0
20 386 0 0 0 0 0 0 0
20 0 0 773 0 0 0 0 0
20 0 0 0 386 0 0 0 0
21 0 290 0 0 0 0 0 0
21 0 0 0 708 0 0 0 0
21 0 0 0 0 354 0 0 0
21 0 0 0 0 0 32 0 0


I would like to sort it all based on the value in Column A. Currently, each row has only 2 (non-zero) values. The first in column A, and another in only ONE of the other columns(B→I). I want to consolidate the rows according to the value in column A. The final product should look like this:
A B C D E F G H I
18 256 512 256 0 0 0 0 0
19 71000 9000 0 0 0 0 140 0
20 386 0 773 386 0 0 0 0
21 0 290 0 708 354 32 0 0


How would I go about doing this?

Thanks in advance.