1 //2016.8.17
 2 #include<iostream>
 3 #include<cstdio>
 4 
 5 using namespace std;
 6 
 7 int phi(int n)
 8 {
 9     int ans = n;
10     for(int i = 2; i <= n; i++)
11     {
12         if(n%i==0)
13         {
14             ans -= ans/i;
15             while(n%i==0)
16                 n /= i;
17         }
18         if(n == 1)break;
19     }
20     return ans;
21 }
22 
23 int main()
24 {
25     int n;
26     while(cin>>n&&n)
27     {
28         cout<<phi(n)<<endl;
29     }
30 
31     return 0;
32 }