/*
 Author                             :     unlucky_13
 Problem_link                       :
 Category                           :
 Algorithm_Used                     :

 */

#include<cstdio>
#include<sstream>
#include<cstdlib>
#include<cctype>
#include<cmath>
#include<algorithm>
#include<set>
#include<queue>
#include<stack>
#include<list>
#include<iostream>
#include<fstream>
#include<numeric>
#include<string>
#include<vector>
#include<cstring>
#include<map>
#include<iterator>
#define i64 long long int
//const long long int inf = 2147483647 ;
//const int minx=;
const i64 maxn=32000;
using namespace std;
//i64 phi[maxn] ;
/*
void sieve()
{


    for(i64 i=0;i<=maxn;i++) phi[i]=i ;

    for(i64 i=2;i<=maxn;i++){
        if(phi[i]==i){
            for(i64 j=2;i*j<=maxn;j++)               // i is a factor of i*j
                phi[i*j] =(phi[i*j]-phi[i*j]/i) ;
        }
    }

}
i64 gcd(i64 a,i64 b){
    while(b>0){
        a =a%b ;
        a ^=b ; b ^=a ; a ^=b ;
    }
    return a ;
}

i64 solve(i64 n)
{
    if(n<=maxn){
        if(phi[n]==n) {
            if(n==1) return 1 ;
            return n-1 ;
        }
        else return phi[n] ;
    }
    i64 N = sqrt(n) ;
    i64 res = n ;
    for(i64 i=2;i<=N;i++){
        if(n%i==0 && gcd(i,n/i)==1) return solve(i)*solve(n/i) ;
    }

    return n-1 ; //this is a prime

}
*/
int phi(int n){
    if(n==1) return 0 ;
    int res = n ;
    if(n%2==0){
        res-=res/2 ;
        while(n%2==0) n/=2 ;
    }

    for(int i=3;i<=sqrt(n);i+=2){
        if(n%i==0){
            res-=res/i ;
            while(n%i==0) n/=i ;
        }
    }
    if(n>1) res-=res/n;
    return res ;

}
int main() {

    freopen("C:\\Users\\Mazhar\\Desktop\\Text_Files\\in.txt", "r", stdin);
    //sieve() ;
    int n ;
    while(1)
    {
        scanf("%d",&n) ;
        if(!n) break ;
        else printf("%d\n",phi(n)) ;
    }




    return 0;
}