Problem E: Relatives
时间: 1ms 内存:128M
描述:
Problem E: Relatives
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.
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.
For each test case there should be single line of output answering the question posed above.
输入:
输出:
示例输入:
7
12
0
示例输出:
6
4
提示:
参考答案:
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