//2017.10.31
 //math
 #include<iostream>
 #include<cstdio>
 #include<cstring>
 using namespace std;
 typedef long long ll ;
 inline ll read();
 namespace lys{
     ll n,ans;
     ll phi(ll x){
         int i;
         ll w=x,res=x;
         ;1LL*i*i<=w;i++){
             if(!(x%i)){
                 res=res*(i-)/i;
                 while(!(x%i)) x/=i;
             }
         }
         ) res=res*(x-)/x;
         return res ;
     }
     int main(){
         int i;
         n=read();
         ;1LL*i*i<=n;i++)
             if(!(n%i)){
                 ans+=phi(n/i)*i;
                 if(1LL*i*i!=n) ans+=phi(i)*(n/i);
             }
         printf("%lld\n",ans);
         ;
     }
 }
 int main(){
     lys::main();
     ;
 }
 inline ll read(){
     ll kk=,ff=;
     char c=getchar();
     '){
         ;
         c=getchar();
     }
     +c-',c=getchar();
     return kk*ff;
 }