#include <bits/stdc++.h>
#define fi first
#define se second

using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");

int n;

int Phi(int n){

  int phi = n;

  for(int d = 2; d*d<=n; ++d)
      if(n%d==0){
         phi/=d;
         phi*=(d-1);
         while(n%d==0)n/=d;
      }

  if(n>1){
     phi/=n;
     phi*=(n-1);
  }

  return phi;

}

int main(){

   ios_base::sync_with_stdio(false);

   f>>n;

   /*
     Complexitate O(n*sqrt(n)) daca fac cu euler

     doar adun Phi pt fiecare nr de la 2 la n si adaug 1 si ala e raspunsul
   */

   return 0;
}