Write a program that reads a non-empty tree of integer numbers and writes its maximum value. Your program should extend the class Tree implemented in file simple_tree.py in the public files section of the problem statement, which can be downloaded by clicking on the ’cat’ icon.
For example, given the following specification of a tree in pre-ordre, where the value stored at each node is followed by its arity
Input
1 4
3 2
6 0
-6 0
12 0
2 4
3 0
5 2
10 0
-13 0
11 0
7 0
8 0
Your program should write Output
12
Hint
Extend the class Tree in file simple_tree.py with a new method maxim with the following header
def maxim(self): ...
and call that method from main after reading the tree.
Input
1 4
3 2
6 0
-6 0
12 0
2 4
3 0
5 2
10 0
-13 0
11 0
7 0
8 0
Output
12