Curency converter

rates = {'BGN': 1.0, 'USD': 1.79549, 'EUR': 1.95583, 'GBP': 2.53405}
inputSum = float(input())
currIn = input()
currOut = input()


def new_currency(curr_code):
    print("Currency rate for {} unavailable! \n To Add new rate type 'YES' \n".format(curr_code))
    answer = input()

    if answer == 'YES':
        print("Add rate for {} : \n".format(curr_code))
        new_rate = float(input())
        new_record = {curr_code: new_rate}
        rates[curr_code] = new_rate
    pass

if rates.get(currIn) is None:
    new_currency(currIn)

if rates.get(currOut) is None:
    new_currency(currOut)

result = inputSum * rates.get(currIn) / rates.get(currOut)
print("{:10.2f}".format(result) + " " + currOut)