#include<iostream>
#include<cstdio>
using namespace std;

int main(){
	int n,i,j,num;
	while(scanf("%d",&n) && n!=0){
		num=n;
		for(i=2;i<=n;i++){
			if(n%i==0){
				num=(num/i)*(i-1);
				while(n%i==0)n/=i;
			}
		}
		printf("%d\n",num);
	}
	
	return 0;
}