# Now write a program that calculates the minimum fixed monthly payment needed in order pay off a credit card balance within 12 months. By a 
# fixed monthly payment, we mean a single number which does not change each month, but instead is a constant amount that will be paid each 
# month.
# In this problem, we will not be dealing with a minimum monthly payment rate.
# The following variables contain values as described below:
# balance - the outstanding balance on the credit card
# annualInterestRate - annual interest rate as a decimal
# The program should print out one line: the lowest monthly payment that will pay off all debt in under 1 year, for example: Lowest Payment: 180 
# Assume that the interest is compounded monthly according to the balance at the end of the month (after the payment for that month is made). 
# The monthly payment must be a multiple of $10 and is the same for all months. Notice that it is possible for the balance to become negative 
# using this payment scheme, which is okay. A summary of the required math is found below:
# Monthly interest rate = (Annual interest rate) / 12.0
# Monthly unpaid balance = (Previous balance) - (Minimum fixed monthly payment)
# Updated balance each month = (Monthly unpaid balance) + (Monthly interest rate x Monthly unpaid balance)
balance = 3926
annualInterestRate = 0.2
fixedPayment = 0
def check_balance(balance, annualInterestRate, fixedPayment):
    
    flag = False
    month = 0
    while month < 12:
        monthlyInterestRate = annualInterestRate / 12.0
        monthlyUnpaidBalance = balance - fixedPayment
        balance = monthlyUnpaidBalance + (monthlyInterestRate * monthlyUnpaidBalance)
        month += 1
    if balance < 0:
        flag = True
    return flag
    
while not check_balance(balance, annualInterestRate, fixedPayment):
    fixedPayment += 10
    
    check_balance(balance, annualInterestRate, fixedPayment)

print("Lowest payment: ", fixedPayment)    
    
                
        
        
    
    
    
                    
        
 
    

    
    
 
