beecrowd | 1051
# Taxes

**Timelimit: 1**

By Neilor Tonin, URI Brasil

In an imaginary country called Lisarb, all the people are very happy to pay their taxes because they know that doesnâ€™t exist corrupt politicians and the taxes are used to benefit the population, without any misappropriation. The currency of this country is Rombus, whose symbol is R$.

Read a value with 2 digits after the decimal point, equivalent to the salary of a Lisarb inhabitant. Then print the due value that this person must pay of taxes, according to the table below.

Remember, if the salary is R$ 3,002.00 for example, the rate of 8% is only over R$ 1,000.00, because the salary from R$ 0.00 to R$ 2,000.00 is tax free. In the follow example, the total rate is 8% over R$ 1000.00 + 18% over R$ 2.00, resulting in R$ 80.36 at all. The answer must be printed with 2 digits after the decimal point.

The input contains only a float-point number, with 2 digits after the decimal point.

Print the message "R$" followed by a blank space and the total tax to be payed, with two digits after the decimal point. If the value is up to 2000, print the message "Isento".

Input Samples | Outputs Samples |

3002.00 |
R$ 80.36 |

1701.12 |
Isento |

4520.00 |
R$ 355.60 |