#include <iostream>
using namespace std;

int main () {
	int n, k;
	
	while (cin >> n and n!=0) {
   	    k = n;
	    for (int i = 2; i*i <= n; i++) {
	        if (n % i == 0) {
	            while (n % i == 0) {
	            	n/= i;
	            }
	            k-=k/i;
	        }
	        
	    }
	    
	    if (n > 1) {
	    	k-=k/n;
	    }
	    
	    cout << k << endl;
	    
    }
    return 0;   
}