Adds together all numbers separated by newlines from input. If an empty line is given, doesn't add anything to the total sum (i.e., it adds 0).
Terminate the program by either sending EOF (Ctrl-D), or with the keyword END. Upon termination, the program will print out the whole sum.
Example:
$ cargo run
1
2018
2
3
-1
END
Total: 2023
$