Biggest sum in triangle?

Question

.........7
3 8
8 1 0
2 7 4 4
4 5 2 6 8
How to find the greatest sum of 2 routes
Both starts from the top to the bottom layer
Overlapped route will only be counted once.
For example:
The 1st route: (7)→3→8→7→5 = 30
The 2nd route: *7→8→1→4→6 = 19
*7 is overlapped with (7) therefore the second 7 doesn't count.

Answer 1

Can you explain better? So there are only two routes? How do we determine these routes? Randomly or input? Why does the overlapped 7 not count? What do you mean by greatest sum of 2 routes?