I have several columns (formatted as text) containing numbers with
dashes, i.e.,

20-1
15-2
30-4
05-3

Is there a way to add up the numbers separately in the column, i.e,
one total for the 20, 15, 20, 05 and one total for the 1, 2, 4, 3. If unable
to add both is it possible to add up just the numbers to the left of the
dash? Thanks.