Transporting Snacks
By Marcio Oshiro, USP 
Brazil
By Marcio Oshiro, USP Brazil
One of the criteria for a programming marathon be considered as a success is that the contestants must not go hungry. Concerned about this, the organization chose one boy dedicated to the task of fetching snacks at supplier. To facilitate the transport of snacks this boy received a wheelbarrow.
Even with the wheelbarrow, this is a very tiresome task, so the organization allowed the boy to eat one of the snacks he carries every 100 meters traveled ( coming or going ) . In addition, each 100 meters, cabanas where he can temporarily store the snacks are prepared. Thus isn't necessary to transport all snacks directly from the supplier to the competition venue.
To know if the boy will ate more snacks than he can, the organization wants you to write a program that determines the maximum amount of snacks that can be delivered . You can assume that the boy eats a snack whenever allowed .
The input consists of several test cases and ends with end of file (EOF). Each test case consists of a line with three integers, L, D, and C (10 ≤ L, D, C ≤ 100,000,000) indicating, respectively, the amount of snacks bought, the distance between the supplier and the competition venue in hectometers and how many snacks fit in the wheelbarrow.
For each test case, print the maximum amount of snacks that can be delivered, if this quantity is positive, or "impossivel" otherwise.
| Sample Input | Sample Output |
|
32 10 20 |
14 |