I have groupings of data in column A. Each group is obviously continguous.
The data grouping are separated by a single blank cell in the column. I
would like to sum the values in each group.

What I have:

A
1000
500
300
200

1000
400
100

1000
1000

What I'd like:

A B
1000
500
300
200
2000
1000
400
100
1500
1000
1000
2000

thanks!