"""
This script demonstrates the use of global variables and the `global` keyword in Python functions.
Global Variables:
- `age`: An integer representing a person's age.
Functions:
- birthday_greet():
    - First definition: Prints a birthday greeting using the global `age` variable, incremented by 1 (without modifying the global variable).
    - Second definition: Uses the `global` keyword to modify the global `age` variable by incrementing it by 1, then prints a birthday greeting.
- birthday_greet_global():
    - First definition: Prints a birthday greeting using the global `age` variable, incremented by 5 (without modifying the global variable).
    - Second definition: Uses the `global` keyword to modify the global `age` variable by incrementing it by 5, then prints a birthday greeting.
Demonstrates:
- The difference between accessing and modifying global variables inside functions.
- The effect of the `global` keyword on variable scope and assignment.
"""
age = 24  

def birthday_greet():
    print(f"Happy B-Day! You are {age + 1}! (local message)")

birthday_greet()                # Call the local function
print("Global message", age)    # Print the global variable   

def birthday_greet_global():
    print(f"Happy B-Day! You are {age + 5}! (global message)")
birthday_greet_global()         # Call the global function  



age = 20

def birthday_greet():
    global age  # Added 'global' keyword
    age += 1
    print(f"Happy B-Day! You are {age}! (local message)")

birthday_greet()
print("Global message", age)    

def birthday_greet_global():
    global age  # Added 'global' keyword
    age += 5
    print(f"Happy B-Day! You are {age}! (global message)")

birthday_greet_global()  # Call the global function