### Relatives

Time Limit: 1500 ms Memory Limit: 10000 KiB

#### Problem 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 Input

7
12
0

#### Sample Output

6
4

#### Hint

nkoj1214 有链接提示的题目请先去链接处提交程序，AC后提交到SDUTOJ中，以便查询存档。

#### Source

1 June, 2002 - Waterloo local contest