Relatives

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
纯欧拉函数
#include<stdio.h>
int lmx(int n)
{
 int i,cnt=1;
 for(i=2;i*i<=n;i++)
 {
  if(n%i==0) 
  {
   n/=i;
   cnt*=i-1;
   while(n%i==0)
   {
    n/=i;
    cnt*=i;
   }
  }
 }
 if(n>1) cnt*=n-1;
 return cnt;
}
int main()
{
 int n;
 while(scanf("%d",&n)&&n)
 {
  printf("%d\n",lmx(n));
 }
}