Appoint description:
Description
For given integer N (1<=N<=104) find amount 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).
Input
Input file contains integer N.
Output
Write answer in output file.
Sample Input
9
Sample Output
6
#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
int n;
int main()
{
scanf("%d",&n);
int m=n;
for(int p=2;n!=1;p++)
{
if(n%p==0)
m=m-m/p;
while(n%p==0)
n=n/p;
}
printf("%d
",m);
return 0;
}