Maximum Edge Removal

Given an undirected tree with an even number of nodes. Consider each connection between a parent and child node to be an edge.

You need to remove maximum number of these edges, such that the disconnected subtrees that remain each have an even number of nodes.

Return the maximum number of edges you can remove.

2 <= A <= 10⁵

1 <= B[i][0], B[i][1] <= A

Integer A will be even.

First argument is an integer A denoting the number of nodes in the tree.

Second argument is a 2D array B of size (A-1) * 2, denoting the edge between nodes B[i][0] and B[i][1].

Return an integer, denoting the maximum number of edges you can remove.

Input 1:

 A = 6
 B = [
       [1, 2]
       [1, 3]
       [1, 4]
       [3, 5]
       [4, 6]
     ]

Input 2:

 A = 2
 B = [
       [1, 2]
     ]

Output 1:

 2

Output 2:

 0

Explanation 1:

      1
    / | \
   2  3  4
      |   \
      5    6
 Maximum number of edges we can remove is 2, i.e (1, 3) and (1, 4)

Explanation 2:

 We can't remove any edges.