# Constants 
CAFFEINE_HALF_LIFE = 6 # hours
def main():
 
 # Get initial caffeine amount
 initial_amount = float(input("Enter the initial caffeine amount (in mg): "))
 
 # Calculate and print caffeine remaining after 6, 12, 24 hours 
 print_caffeine_remaining(initial_amount, 6)
 print_caffeine_remaining(initial_amount, 12) 
 print_caffeine_remaining(initial_amount, 24)
def print_caffeine_remaining(initial_amount, hours_passed):
 """Prints the caffeine remaining after the given hours, rounded to 2 decimals"""
 
 amount_remaining = calculate_remaining(initial_amount, hours_passed)
 
 print(f"After {hours_passed} hours: {amount_remaining:.2f}mg")
 
def calculate_remaining(initial_amount, hours_passed):
 """Calculates the caffeine remaining based on half-life formula"""
 return initial_amount * (0.5)**(hours_passed / CAFFEINE_HALF_LIFE)
if __name__ == "__main__":
 main()