2047. Coprimes

单点时限: 2.0 sec

内存限制: 256 MB

For given integer N (1<=N<=10^4) find amout of positive numbers not greater than N that coprime with N. Let us call two positive integers (say, A and B, for example) coprime if (and only if) their greatest common divisor is 1. (i.e. A and B are coprime iff gcd(A,B) = 1).

输入格式

There are so many tests.Each line contains integer N.

输出格式

Write answer in output file.

样例

Input
9
Output
6

46 人解决,71 人已尝试。

59 份提交通过,共有 250 份提交。

4.8 EMB 奖励。

创建: 17 年前.

修改: 7 年,3 月前.

最后提交: 3 年前.

来源: N/A

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