You have just started a sales job in a department store. Your pay consists of a base salary and a commission. The base salary is $5,000. The scheme shown below is used to determine the commission rate.

Sales Amount                                          Commission Rate
$0.01–$5,000 ...........................................      8 percent
$5,000.01–$10,000 ..................................    10 percent
$10,000.01 and above ...........................     12 percent

Note that this is a graduated rate. The rate for the first $5,000 is at 8%, the next $5000 is at 10%, and the rest is at 12%. If the sales amount is 25,000, the commission is 5,000 * 8% + 5,000 * 10% + 15,000 * 12% = 2,700.

Your goal is to earn $30,000 a year. Write a program that finds the minimum sales you have to generate in order to make $30,000.