# Debt Payment Calculator

#Takes in the necessary variables for the calculator
outstanding_bal = float(raw_input('Please enter the outstanding balance on your credit card: '))
annual_interest = float(raw_input('Please enter the annual credit card interest rate as a decimal: '))
monthly_interest = annual_interest/12.0

outstanding_bal_copy = outstanding_bal

month = 1

lower_payment = outstanding_bal_copy / 12.0
upper_payment = (outstanding_bal_copy *(1+(annual_interest/12))**12.0)/12.0

monthly_payment = (upper_payment + lower_payment) / 2.0


#Finds the optimal monthly payment with interest
while (outstanding_bal_copy > 0):
    ##print monthly_payment
    ##print outstanding_bal_copy
    outstanding_bal_copy = round((outstanding_bal_copy * (1 + monthly_interest) - monthly_payment), 2)
    if month > 12:
        month = 1
        if outstanding_bal_copy > 0:
            upper_payment = monthly_payment
        else:
            lower_payment = monthly_payment
        monthly_payment = (upper_payment + lower_payment) / 2.0
        outstanding_bal_copy = outstanding_bal
        continue
    month += 1

month = month - 1

if outstanding_bal_copy <= 0:
    print 'RESULT'
    print 'Monthly payment to pay off debt in 1 year: $' + str(monthly_payment)
    print 'Number of months needed: ' + str(month)
    print 'Balance: $' + str(outstanding_bal_copy)