Uluthando needs your help to plant some trees. He can give you three parameters of the land:

- width of the land w
- length of the land l
- gap between the trees g
You have to create an algorithm to return the number of trees which can be planted on the edges of the given land in a symmetrical layout shown below (unsymmetrical gap = x, tree = o, gap = -):

w=3, l=3, g=1
plantTrees(w, l, g) ➞ 4

o - o
- -
o - o

// Uluthando can plant 4 trees.
w=3, l=3, g=3
plantTrees(w, l, g) ➞ 2

o - -
- -
- - o

// Uluthando can plant 2 trees.
If the layout is not symmetrical, you have to return 0:

w=3, l=3, g=2
plantTrees(w, l, g) ➞ 0

o - -
x o
x x x

// Planting 2 trees mean the gap of two trees will be greater than 2.

o - -
x o
o - -

// Planting 3 trees mean the gap of two trees will be less than 2.
Another Example for better understanding:

w=3, l=3, g=0
plantTrees(w, l, g) ➞ 8

o o o
o o
o o o

// Uluthando can plant 8 trees​