Problems
Trailing Sifar
Trailing Sifar
Sifar is a malay word for zero or 0. In mathematics, trailing sifar is a sequence of 0s in the decimal representation of a number after which no other digits follow.
The number of trailing sifar in the decimal representation of N! (5 ≤ N ≤ 1000000) is simply the multiplicity of the prime factor 5 in N!. Given a decimal integer N, you are to find the number of trailing sifar for N!
For example, 10! = 3628800. Thus, the number of trailing sifar for 10! is 2.
Input data
Each line of input contains an integer N where 5 ≤ N ≤ 1000000. The input is terminated with a line containing 0.
Output data
For each test case, the output contains a line in the format Case #x: M, where x is the case number (starting from 1) and M is the number of trailing sifar for N!
Examples
Input example #1
5 10 118 211 0
Output example #1
Case #1: 1 Case #2: 2 Case #3: 27 Case #4: 51