UVa 11723 - Numbering Roads

Summary
It's a simple mathematical problem. Your Task is to find out the minimum number of possibility to numbering all the roads with the given number of roads & numbers.

Explanation
The solution of this problem is the answer of this: (number of road - 1)/number of numbers.

Implementations
Take road number & number of numbers as long long integer.

Input
8 5

100 2

0 0

Output
Case 1: 1

Case 2: impossible