Diagonal 

The number of diagonals of an n-gon is not less than N. What is the minimum possible value of n?

Input 

The input file contains less than 1001 lines of inputs. Each line contains a positive integer N ( N$\le$10¹⁵) that indicates the minimum possible number of diagonals. Input is terminated by a line containing a zero. This line should not be processed.

Output 

For each line of input produce one line of output, which contains the output serial number, and also the minimum possible value for n (Number of sides).

Sample Input 

10
100
1000
0

Sample Output 

Case 1: 7
Case 2: 16
Case 3: 47