## #1305 Relatives

12  1 s   66 MB

## Description

Given n, a positive integer, how many positive integers less than n are relatively prime to n? Two integers a and b are relatively prime if there are no integers x > 1, y > 0, z > 0 such that a = xy and b = xz.

## Input

There are several test cases. For each test case, standard input contains a line with n <= 1,000,000,000. A line containing 0 follows the last case.

## Output

For each test case there should be single line of output answering the question posed above.

### Sample Output

7
12
0

6
4