#ARAを計算する関数
# damage_amount : 損害額の絶対値
# damage_probability  : 損害が発生する確率  (0.3)
# payment_intention_amount : 支払意思額

def calculate_ARA(damage_amount, payment_intention_amount):
    damage_probability = 0.3
    numerator = damage_amount * damage_probability - payment_intention_amount
    denominator = (
        (damage_probability * damage_amount * damage_amount)
        - (2 * damage_probability * payment_intention_amount * damage_amount)
        + (payment_intention_amount * payment_intention_amount) 
        ) / 2

    ARA = numerator / denominator
    
    return ARA

### For Testing

a = input("損害額: ")
b = input("支払意思額: ")

result = calculate_ARA(float(a), float(b))
print("not round: " + str(result))
print("round: " + str(round(result, 10)))

###