1 #include<cstdio>
 2 #include<iostream>
 3 #define LL long long
 4 using namespace std;
 5 
 6 LL x;
 7 
 8 LL euler(LL x){
 9     LL ans = 1;
10     for(LL i = 2;i*i <= x;i++){
11         if(x%i) continue;
12         ans *= i-1;
13         x /= i;
14         while(x%i == 0){
15             ans *= i;
16             x /= i;
17         }
18     }if(x > 1) ans *= x-1;
19     return ans;
20 }
21 
22 int main(){
23     scanf("%I64d",&x);
24 
25     LL tot = 0;
26 
27     for(int i = 1;i*i <= x;i++){
28         if(x%i) continue;
29         LL t = x/i;
30         tot += i*euler(t);    
31         if(i != t) tot += t*euler(x/t);
32     }cout << tot;
33     
34     return 0;
35 }