int oula(int n)
{
	int cnt=1;
	for(int 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;
}

#include<iostream>
#include<cstdio>
#include<string.h>
#include<string>
using namespace std;
#define maxn 1000000000
int oula(int n)
{
	int cnt=1;
	for(int 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))
	{
		if(n==0)
			break;
		printf("%d\n",oula(n));
	}
	return 0;
}