The number of diagonals of an n-gon is not less than N. What is the minimum possible value of n?
Contains less than 1001 lines. Each line contains a positive integer N (N ≤
1015) that indicates the minimum possible number of diagonals. Input is terminated by a line with one 0 that should not be processed.
For each test case produce one line that contains serial number and the minimum possible value for n (number of sides).
10 100 1000 0
Case 1: 7 Case 2: 16 Case 3: 47