oal: Learn to read structured files line by line.

Assignment: A file named units.txt records the contents of the containers in a logistic hub. Each line contains the number of items, and each container section is separated from the next by a line with a dash. The following is an example file:

Contents of units.txt

$10$

$123$

$95$

$-$

$285$

$64$

Write some code that creates a file named totals.txt in which each line is the sum of all the item counts per container section. Continuing the above example, the following is the example result:

Contents of totals.txt

$228$

$349$