北大OJ2407

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
	int n,i,j,number;
	while(scanf("%d",&n)!=EOF&&n)
	{
		number=n;
		for(i=2;i<=n;i++)
		{
			if(n%i==0)
			{
				number=number/i*(i-1);
				while(n%i==0) n/=i;
			}
		}
		printf("%d\n",number);
	}
	return 0;
}