题目描述

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.

有多组数据，每组一个整数 $n (n \le 10^9)$ ，求出在小于 $n$ 的正整数中与 $n$ 互质的数的个数， 最后以 $0$ 结束。

输入格式

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.

输出格式

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

样例

7
12
0

6
4