This is the third and final entry in my Cross Sums series. This will be the toughest of the three, especially without the starting hint, but don't despair! Whether you work on it by yourself or with a PAF you'll be able to make it across the finish line! There is $5.00 and one of my new PathTags for the FTF.

The rules remain the same:
The numbers in the black squares refer to the sum of the digits to be filled into the empty squares.
The number below a diagonal line is the sum of the numbers below it.
The number above a diagonal line is the sum of the numbers to the right of it.
Place one digit, using 1 to 9 (no zeros) in each empty square.
Numbers cannot repeat within any particular digit combination.
For example, if the puzzle calls for two digits that add up to 4, the only possible combination of numbers that can be used are 1 and 3. (Using 2 and 2 is not allowed.)
You will notice a group of squares that have a heavy outline around them. This is a place for a starting hint. I will post the numbers that go into this outlined area after one week, although I'm sure the puzzle will have been solved by then.
When the puzzle has been completed, use the following to get the numbers you need to move on:
M2 K11 F10 B13 E8 D5 H7 D13 C2 N8 (checksum = 52)
Congratulations to Mud Dancer for being the FTS, and to Mud Dancer and Team Daisydog for their co-FTF!

You can validate your puzzle solution with certitude.