1448: Relatives
内存限制：128 MB
时间限制：1.000 S
评测方式：文本比较
命题人：
提交：5
解决：3
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.
输入
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
For each test case there should be single line of output answering the question posed above.
样例输入 复制
7
12
0样例输出 复制
6
4提示
练习赛9-E