def show_balance():
print(f"Your balance is:${balance:.2f}")

def deposit():
amount = float(input("How much amount do you want to deposit? "))
if amount < 0:
print("That is not a valid amount.")
return 0
else:
return amount

def withdraw():
amount = float(input("How much amount do you want to withdraw? "))
if amount > balance:
print("You don't have enough money to withdraw.")
return 0
else:
return amount

balance = 0
is_running = True

while is_running:
print("Banking program")
print("1. Show Balance")
print("2. Deposit")
print("3. Withdraw")
print("4. Exit")

choice = input("Enter your choice (1 - 4) : ")
if choice == "1":
    show_balance()
elif choice == "2":
    balance += deposit()
elif choice == "3":
    balance -= withdraw()
elif choice == "4":
    is_running = False
else:
    print("That is not a Invalid choice")

print("Thank you! have a nice day!")