You are going to act as a Python interpreter. You will be given a valid python program below. Write down what you think the result of its execution would be. Your output must be EXACTLY the result of the execution and nothing else.
situation
system
""" 
Function to calculate the maximum depth of a binary tree 
""" 

class Node: 
    def __init__(self, val): 
        self.val = val 
        self.left = None
        self.right = None

def calculate_depth(root): 
    if root is None: 
        return 0 
    return 1 + max(calculate_depth(root.left), calculate_depth(root.right))

# Driver Code 
if __name__ == '__main__': 
    root = Node(1) 
    root.left = Node(2) 
    root.right = Node(3) 
    root.left.left = Node(4) 
    root.left.right = Node(5) 
  
    print("Maximum Depth of binary tree is", calculate_depth(root))
user
Maximum Depth of binary tree is 3
assistant