print("This program calculates the sum of the numbers you enter.")
print("Enter numbers one at a time. Type 'STOP' when you are finished.\n")

total = 0

while True:
    user_input = input("Enter a number: ")
    
    if user_input.strip().lower() == "stop":
        break
    
    try:
        number = float(user_input)
        total += number
        print("Current total:", total)
    except ValueError:
        print("Invalid input. Please enter a number or STOP.")

print("\nFinal total:", total)